The full picture is always a bit nuanced though so to expand on that: I have tried it cursorily with rust [using wachy to trace wachy :)] and it appears to work. The one issue I would say is that wachy is currently hardcoded to use C++ symbol demangling, so rust function names are not completely accurate (although it's surprisingly decent) - please open an issue if you want that fixed (or if you run into any other issues)! I decided it's better to get it out there and improve things that people actually use rather than fix all my TODOs (excuses for being lazy).
And with rust async, I haven't tried it myself but looked into the details some time back. Wachy works by simply looking at function entry/exit timestamps, but the rust aysnc impl is using futures + poll rather than saving and restoring stacks, so it's not gonna work. You can presumably trace the future's poll function, which may or may not be useful. Although, perhaps with some custom eBPF logic and examining the poll return value it could be made to work...