Headless Linux, actual Bash PTY and /bin/ps process table, default 1-second poll.
Base ab6be13d43, head 8aa273292331510e1f418ae0faebf288c2bb4717.
Same 12-second idle window, sleep 3 input, 5-second post-exit quiet window.

BEFORE (main)
(node:162634) ExperimentalWarning: Transform Types is an experimental feature and might change at any time
(Use `node --trace-warnings ...` to show where the warning was created)
{"phase":"idle12s","snapshots":11,"pid":162646}
{"event":"register","processIds":[162646,162894],"at":12592}
{"phase":"child-start","event":{"type":"activity","threadId":"tp11-live","terminalId":"default","sequence":5,"hasRunningSubprocess":true,"label":"sleep"},"snapshots":12,"at":12594}
{"event":"register","processIds":[162646,162894],"at":13668}
{"event":"register","processIds":[162646,162894],"at":14719}
{"phase":"child-exit","event":{"type":"activity","threadId":"tp11-live","terminalId":"default","sequence":7,"hasRunningSubprocess":false,"label":"default"},"snapshots":15,"at":15775}
{"phase":"quiet-again","snapshots":19}
{"phase":"complete","snapshots":19}

AFTER (PR head)
(node:166752) ExperimentalWarning: Transform Types is an experimental feature and might change at any time
(Use `node --trace-warnings ...` to show where the warning was created)
{"phase":"idle12s","snapshots":2,"pid":166869}
{"event":"register","processIds":[166869,167239],"at":12142}
{"phase":"child-start","event":{"type":"activity","threadId":"tp11-live","terminalId":"default","sequence":4,"hasRunningSubprocess":true,"label":"sleep"},"snapshots":3,"at":12142}
{"event":"register","processIds":[166869,167239],"at":13181}
{"event":"register","processIds":[166869,167239],"at":14202}
{"phase":"child-exit","event":{"type":"activity","threadId":"tp11-live","terminalId":"default","sequence":6,"hasRunningSubprocess":false,"label":"default"},"snapshots":6,"at":15221}
{"phase":"quiet-again","snapshots":7}
{"phase":"complete","snapshots":7}