I just read your post and don't think it would take much to integrate with some of the visualisations you posted about, as a first step.

We've played around in the past with a sampling profiler (code here, requires a copy of our product to be useful though it could easily port to rr): https://github.com/undoio/addons/tree/master/sample_function... which can output in a format understood by Brendan Gregg's flame frames (https://www.brendangregg.com/flamegraphs.html)

But that's not quite the kind of tracing you're talking about. We also built a printf-style interface to our recording files, which seems closer: https://docs.undo.io/PostFailureLogging.html

Something like that but outputting trace events that can be consumed by Perfetto (say) would not be so hard to add. If we considered modifying the core record/replay engine then even more powerful things become possible.