REAL SERVER DELEGATION PERFORMANCE CAPTURE
Environment: Linux x86_64; 8 vCPUs AMD EPYC 9455; Node 26.13.1; same VM; sequential servers.
Fresh database per revision; T3CODE_DEV_SEED=0; synthetic ACP provider; real MCP requests.
100 cycles of 400 completed tool calls + 7 quick delegated tasks.
Per size: 7 rounds of 3 quick tasks/status reads + 3 long tasks/cancellations/terminal checks.
Round 0 is warm-up; all remaining six rounds are used. Median = median of round medians.
Spread = maximum - minimum of the six round medians. Units are milliseconds.
Read scopes are defined in method.md. Whole outer-finalize timings include inner completion.

BEFORE dbbbe8b0d6efca2c27d331d0435d473192b0b69f
Large parent before measurement: {"runs": 373, "nodes": 41446, "subagents": 700, "turn_items": 41820}
  LARGE
    Task start / operation: 180.859921 [162.603852, 239.064378], spread 76.460526
      rounds: 0=warm:244.318774 (n=6), 1=239.064378 (n=6), 2=180.846500 (n=6), 3=194.058340 (n=6), 4=162.603852 (n=6), 5=177.670042 (n=6), 6=180.873342 (n=6)
    Task start / store: 69.883404 [62.027354, 75.880951], spread 13.853597
      rounds: 0=warm:72.331820 (n=6), 1=75.880951 (n=6), 2=75.720567 (n=6), 3=63.067181 (n=6), 4=64.491716 (n=6), 5=62.027354 (n=6), 6=75.275091 (n=6)
    Task completion / operation: 898.874840 [822.398362, 967.819998], spread 145.421636
      rounds: 0=warm:917.008856 (n=6), 1=967.819998 (n=6), 2=912.247800 (n=6), 3=964.742867 (n=6), 4=842.134267 (n=6), 5=822.398362 (n=6), 6=885.501879 (n=6)
    Task completion / store: 851.759280 [760.955813, 946.011398], spread 185.055585
      rounds: 0=warm:854.853019 (n=6), 1=946.011398 (n=6), 2=873.221654 (n=6), 3=899.933685 (n=6), 4=803.721969 (n=6), 5=760.955813 (n=6), 6=830.296905 (n=6)
    Finalize outer (includes completion) / operation: 85.109861 [77.614744, 100.904057], spread 23.289313
      rounds: 0=warm:89.749799 (n=18), 1=100.904057 (n=18), 2=99.696945 (n=18), 3=83.483677 (n=18), 4=78.787762 (n=18), 5=77.614744 (n=18), 6=86.736046 (n=18)
    Status synchronization / store: 55.811149 [51.068751, 60.689101], spread 9.620350
      rounds: 0=warm:55.659754 (n=18), 1=57.241394 (n=18), 2=57.187511 (n=18), 3=53.287340 (n=18), 4=54.434787 (n=18), 5=51.068751 (n=18), 6=60.689101 (n=18)
    Task cancellation / operation: 1147.357376 [1075.188654, 1254.533289], spread 179.344635
      rounds: 0=warm:1089.863295 (n=3), 1=1186.133550 (n=3), 2=1254.533289 (n=3), 3=1250.305228 (n=3), 4=1075.188654 (n=3), 5=1082.372533 (n=3), 6=1108.581202 (n=3)
    Task cancellation / store: 10.110635 [8.766899, 12.680730], spread 3.913831
      rounds: 0=warm:9.908564 (n=3), 1=9.389540 (n=3), 2=12.018300 (n=3), 3=9.394854 (n=3), 4=10.826416 (n=3), 5=8.766899 (n=3), 6=12.680730 (n=3)
  TINY
    Task start / operation: 136.081693 [121.424389, 163.682446], spread 42.258057
      rounds: 0=warm:136.205881 (n=6), 1=163.682446 (n=6), 2=158.934573 (n=6), 3=132.627916 (n=6), 4=133.161858 (n=6), 5=139.001528 (n=6), 6=121.424389 (n=6)
    Task start / store: 16.341484 [13.538971, 18.084470], spread 4.545499
      rounds: 0=warm:15.511807 (n=6), 1=18.084470 (n=6), 2=16.515087 (n=6), 3=16.167882 (n=6), 4=17.692462 (n=6), 5=14.793139 (n=6), 6=13.538971 (n=6)
    Task completion / operation: 108.549189 [103.697358, 141.981093], spread 38.283735
      rounds: 0=warm:129.783839 (n=6), 1=108.141363 (n=6), 2=105.395865 (n=6), 3=103.697358 (n=6), 4=141.981093 (n=6), 5=124.022492 (n=6), 6=108.957015 (n=6)
    Task completion / store: 28.137262 [22.920780, 34.758502], spread 11.837722
      rounds: 0=warm:33.306025 (n=6), 1=23.602305 (n=6), 2=22.920780 (n=6), 3=29.771271 (n=6), 4=26.503253 (n=6), 5=34.758502 (n=6), 6=31.023779 (n=6)
    Finalize outer (includes completion) / operation: 65.028424 [31.310584, 79.881921], spread 48.571337
      rounds: 0=warm:72.118783 (n=12), 1=60.449432 (n=12), 2=63.466878 (n=12), 3=31.310584 (n=13), 4=79.881921 (n=12), 5=66.589971 (n=12), 6=68.517855 (n=12)
    Status synchronization / store: 2.745105 [2.440335, 9.727778], spread 7.287443
      rounds: 0=warm:2.285570 (n=12), 1=2.440335 (n=12), 2=2.602328 (n=12), 3=2.509929 (n=13), 4=2.887882 (n=12), 5=5.561395 (n=12), 6=9.727778 (n=12)
    Task cancellation / operation: 244.094021 [201.654234, 268.439857], spread 66.785623
      rounds: 0=warm:288.346130 (n=3), 1=232.836054 (n=3), 2=214.057796 (n=3), 3=268.439857 (n=3), 4=260.337622 (n=3), 5=201.654234 (n=3), 6=255.351988 (n=3)
    Task cancellation / store: 0.594149 [0.426215, 2.878759], spread 2.452544
      rounds: 0=warm:2.864527 (n=3), 1=0.446596 (n=3), 2=0.426215 (n=3), 3=0.605501 (n=3), 4=0.582798 (n=3), 5=0.705412 (n=3), 6=2.878759 (n=3)
Persisted behavior: [{"delivery": {"acknowledged": 21, "delivered": 700, "disposed": 21}, "parent": "Large synthetic parent", "resultTexts": {"Synthetic task complete.": 742}, "results": 742, "statuses": {"completed": 721, "interrupted": 21}, "tasks": 742}, {"delivery": {"acknowledged": 21, "disposed": 21}, "parent": "Tiny synthetic parent", "resultTexts": {"Synthetic task complete.": 42}, "results": 42, "statuses": {"completed": 21, "interrupted": 21}, "tasks": 42}]
Provider transcript summary: {"cancelRequests": 42, "cancelTerminals": 42, "completedStatusReads": 42, "errors": [], "prompts": {"PROOF:LONG": 42, "PROOF:MEASURE": 14, "PROOF:QUICK": 742, "PROOF:SEED 0": 2, "PROOF:SEED 400": 100, "PROOF:TASKS 7": 100, "wake": 172}}

AFTER 6dc09c0c28ae197417f6e6ac7c4f0127d7fc4c55
Large parent before measurement: {"runs": 401, "nodes": 41502, "subagents": 700, "turn_items": 41904}
  LARGE
    Task start / operation: 128.512811 [104.734483, 136.575404], spread 31.840921
      rounds: 0=warm:151.009426 (n=6), 1=133.080179 (n=6), 2=104.734483 (n=6), 3=129.341229 (n=6), 4=136.575404 (n=6), 5=108.427627 (n=6), 6=127.684393 (n=6)
    Task start / store: 14.076295 [9.245344, 22.692721], spread 13.447376
      rounds: 0=warm:15.869705 (n=6), 1=20.010711 (n=6), 2=22.692721 (n=6), 3=10.840089 (n=6), 4=15.452844 (n=6), 5=12.699747 (n=6), 6=9.245344 (n=6)
    Task completion / operation: 132.715860 [102.741435, 148.732396], spread 45.990960
      rounds: 0=warm:126.430943 (n=6), 1=135.300646 (n=6), 2=136.550046 (n=6), 3=148.732396 (n=6), 4=129.241401 (n=6), 5=102.741435 (n=6), 6=130.131074 (n=6)
    Task completion / store: 14.132472 [11.395125, 15.093367], spread 3.698242
      rounds: 0=warm:20.185137 (n=6), 1=14.986768 (n=6), 2=13.652850 (n=6), 3=14.612095 (n=6), 4=13.510457 (n=6), 5=15.093367 (n=6), 6=11.395125 (n=6)
    Finalize outer (includes completion) / operation: 66.169353 [63.094121, 76.445069], spread 13.350948
      rounds: 0=warm:84.935817 (n=12), 1=73.044241 (n=12), 2=76.445069 (n=12), 3=66.206999 (n=12), 4=63.912521 (n=12), 5=63.094121 (n=12), 6=66.131708 (n=12)
    Status synchronization / store: 2.252375 [2.085510, 2.402538], spread 0.317028
      rounds: 0=warm:2.910916 (n=12), 1=2.298659 (n=12), 2=2.230572 (n=12), 3=2.085510 (n=12), 4=2.402538 (n=12), 5=2.274178 (n=12), 6=2.141087 (n=12)
    Task cancellation / operation: 217.154138 [209.648915, 291.720945], spread 82.072030
      rounds: 0=warm:341.647529 (n=3), 1=258.830398 (n=3), 2=291.720945 (n=3), 3=216.647783 (n=3), 4=217.660494 (n=3), 5=209.648915 (n=3), 6=215.388016 (n=3)
    Task cancellation / store: 0.364013 [0.328039, 0.414538], spread 0.086499
      rounds: 0=warm:0.515489 (n=3), 1=0.328039 (n=3), 2=0.376601 (n=3), 3=0.414538 (n=3), 4=0.351425 (n=3), 5=0.335151 (n=3), 6=0.399137 (n=3)
  TINY
    Task start / operation: 143.264527 [121.530638, 169.734706], spread 48.204069
      rounds: 0=warm:123.749676 (n=6), 1=154.785892 (n=6), 2=139.044640 (n=6), 3=147.484414 (n=6), 4=132.538781 (n=6), 5=169.734706 (n=6), 6=121.530638 (n=6)
    Task start / store: 13.509976 [9.433125, 17.586144], spread 8.153019
      rounds: 0=warm:6.213783 (n=6), 1=17.586144 (n=6), 2=17.559697 (n=6), 3=9.433125 (n=6), 4=9.762967 (n=6), 5=12.941132 (n=6), 6=14.078820 (n=6)
    Task completion / operation: 121.192048 [103.167207, 131.770882], spread 28.603675
      rounds: 0=warm:121.767334 (n=6), 1=117.239556 (n=6), 2=103.167207 (n=6), 3=119.969299 (n=6), 4=122.414796 (n=6), 5=125.111074 (n=6), 6=131.770882 (n=6)
    Task completion / store: 16.044475 [10.045009, 21.472106], spread 11.427097
      rounds: 0=warm:10.962595 (n=6), 1=21.472106 (n=6), 2=15.804483 (n=6), 3=12.951779 (n=6), 4=16.284468 (n=6), 5=21.005923 (n=6), 6=10.045009 (n=6)
    Finalize outer (includes completion) / operation: 67.113737 [52.550887, 81.378499], spread 28.827613
      rounds: 0=warm:43.512064 (n=14), 1=68.762417 (n=12), 2=65.465058 (n=12), 3=81.378499 (n=12), 4=58.647430 (n=12), 5=52.550887 (n=12), 6=76.371191 (n=12)
    Status synchronization / store: 2.547650 [1.657326, 5.267328], spread 3.610001
      rounds: 0=warm:2.316614 (n=14), 1=2.923586 (n=12), 2=5.267328 (n=12), 3=2.171713 (n=12), 4=1.657326 (n=12), 5=1.750416 (n=12), 6=5.144373 (n=12)
    Task cancellation / operation: 233.989939 [193.174096, 294.144107], spread 100.970011
      rounds: 0=warm:282.148332 (n=3), 1=255.907154 (n=3), 2=193.174096 (n=3), 3=294.144107 (n=3), 4=212.072724 (n=3), 5=196.137366 (n=3), 6=276.255266 (n=3)
    Task cancellation / store: 0.263888 [0.217334, 0.328219], spread 0.110885
      rounds: 0=warm:0.206277 (n=3), 1=0.239397 (n=3), 2=0.295100 (n=3), 3=0.217334 (n=3), 4=0.279807 (n=3), 5=0.247969 (n=3), 6=0.328219 (n=3)
Persisted behavior: [{"delivery": {"acknowledged": 21, "delivered": 700, "disposed": 21}, "parent": "Large synthetic parent", "resultTexts": {"Synthetic task complete.": 742}, "results": 742, "statuses": {"completed": 721, "interrupted": 21}, "tasks": 742}, {"delivery": {"acknowledged": 21, "disposed": 21}, "parent": "Tiny synthetic parent", "resultTexts": {"Synthetic task complete.": 42}, "results": 42, "statuses": {"completed": 21, "interrupted": 21}, "tasks": 42}]
Provider transcript summary: {"cancelRequests": 42, "cancelTerminals": 42, "completedStatusReads": 42, "errors": [], "prompts": {"PROOF:LONG": 42, "PROOF:MEASURE": 14, "PROOF:QUICK": 742, "PROOF:SEED 0": 2, "PROOF:SEED 400": 100, "PROOF:TASKS 7": 100, "wake": 200}}

LARGE PARENT BASE -> HEAD COMPARISON
[
  {
    "action": "Task start",
    "scope": "store",
    "baseMedianMs": 69.88340375,
    "headMedianMs": 14.076295250000001,
    "gainMs": 55.8071085,
    "baseSpreadMs": 13.853597000000008,
    "headSpreadMs": 13.447376499999999,
    "combinedSpreadMs": 27.300973500000005,
    "exceedsEachSpread": true,
    "exceedsCombinedSpread": true,
    "nonoverlappingRoundMedians": true
  },
  {
    "action": "Task start",
    "scope": "operation",
    "baseMedianMs": 180.85992124999999,
    "headMedianMs": 128.51281125,
    "gainMs": 52.34710999999999,
    "baseSpreadMs": 76.46052649999999,
    "headSpreadMs": 31.84092149999998,
    "combinedSpreadMs": 108.30144799999997,
    "exceedsEachSpread": false,
    "exceedsCombinedSpread": false,
    "nonoverlappingRoundMedians": true
  },
  {
    "action": "Task completion",
    "scope": "store",
    "baseMedianMs": 851.7592795,
    "headMedianMs": 14.132472250000001,
    "gainMs": 837.6268072500001,
    "baseSpreadMs": 185.05558499999995,
    "headSpreadMs": 3.698242499999999,
    "combinedSpreadMs": 188.75382749999994,
    "exceedsEachSpread": true,
    "exceedsCombinedSpread": true,
    "nonoverlappingRoundMedians": true
  },
  {
    "action": "Task completion",
    "scope": "operation",
    "baseMedianMs": 898.87483975,
    "headMedianMs": 132.71586025,
    "gainMs": 766.1589795,
    "baseSpreadMs": 145.42163600000003,
    "headSpreadMs": 45.9909605,
    "combinedSpreadMs": 191.41259650000003,
    "exceedsEachSpread": true,
    "exceedsCombinedSpread": true,
    "nonoverlappingRoundMedians": true
  },
  {
    "action": "Status synchronization",
    "scope": "store",
    "baseMedianMs": 55.8111495,
    "headMedianMs": 2.252375,
    "gainMs": 53.5587745,
    "baseSpreadMs": 9.620349500000003,
    "headSpreadMs": 0.3170280000000001,
    "combinedSpreadMs": 9.937377500000004,
    "exceedsEachSpread": true,
    "exceedsCombinedSpread": true,
    "nonoverlappingRoundMedians": true
  },
  {
    "action": "Status synchronization",
    "scope": "operation",
    "baseMedianMs": 85.10986125,
    "headMedianMs": 66.16935325,
    "gainMs": 18.940507999999994,
    "baseSpreadMs": 23.289312999999993,
    "headSpreadMs": 13.350947500000004,
    "combinedSpreadMs": 36.6402605,
    "exceedsEachSpread": false,
    "exceedsCombinedSpread": false,
    "nonoverlappingRoundMedians": true
  },
  {
    "action": "Task cancellation",
    "scope": "store",
    "baseMedianMs": 10.110635,
    "headMedianMs": 0.36401300000000003,
    "gainMs": 9.746622,
    "baseSpreadMs": 3.913831,
    "headSpreadMs": 0.08649899999999999,
    "combinedSpreadMs": 4.00033,
    "exceedsEachSpread": true,
    "exceedsCombinedSpread": true,
    "nonoverlappingRoundMedians": true
  },
  {
    "action": "Task cancellation",
    "scope": "operation",
    "baseMedianMs": 1147.357376,
    "headMedianMs": 217.1541385,
    "gainMs": 930.2032374999999,
    "baseSpreadMs": 179.34463499999993,
    "headSpreadMs": 82.07202999999998,
    "combinedSpreadMs": 261.4166649999999,
    "exceedsEachSpread": true,
    "exceedsCombinedSpread": true,
    "nonoverlappingRoundMedians": true
  }
]

LIMITATIONS
Heap and decoded/allocated bytes were not measured.
These are in-app read spans, not the PR author's standalone warm DB-copy microbenchmark.
Cancellation's interrupt-existence lookup is not separately isolated.
Startup task-numbering counts and residual provider-turn scanning are not separately measured.