This skill is complementary to argent-react-native-optimization, not a replacement for it.

Physical iPhone: not supported; react-profiler-* reject kind: "device". Profile on a simulator.

1. Tools

react-profiler-start / react-profiler-stop: record CPU samples and React commits around an interaction.
react-profiler-analyze: turn the recording into a ranked report: hot commits with the JS functions that ran during each.
react-profiler-status: only after an interruption (debugger drop, Metro reload, pause, subagent handoff, any doubt), never otherwise. A debugger drop also ends the recording; check status before stopping or restarting.
react-profiler-component-source: source, location and memoization status of a component the report flagged.
react-profiler-renders: how many instances of each component are mounted in the top 30 levels of the tree, with their last render time; no session needed. It does not count re-renders: record a profile for that.
react-profiler-fiber-tree: live component hierarchy, no session needed, for tracing a component's ancestry.

argent-react-native-profiler