Author here, yep, I agree, not a bug, just what you get if you start accessing raw stuff instead of stable interfaces and underlying things change (but in this case it was necessary). I mentioned this in the summary in the end.

My understanding is that with BTF + CO-RE, you'll have the flexibility of building your program binary once and it will work on other (BTF+CORE capable) kernel versions without without needing a recompile. But since I had to use lower level methods for stack & pt_regs access, I had to manually add logic for checking kernel structural differences at runtime.

That being said, I have not yet gotten to test if a compiled xcapture binary can just be copied between machines (of the same architecture) and whether it really works as advertised...