I also wonder what the perf overhead will be for programs that only need i32. I didn’t dig deep enough on the implementation, but these type of variadic runtime options often cause perf regressions because of all the “ifs” / lookups of type configs/parameters, etc. I just imagine some inner loops where mem.get adds a few instructions from the “if u32/64/“.

Unless it ends up being seamless / no cost via loading different u32/u64 implementations.

I mostly agree with the old c++ mantra of - no feature should have a runtime cost unless used.