This list is a good forum to discuss changes, so feel free to use it.
Performance instrumentation, in particular on the level that you
suggested, is something very useful. It is very helpful to know how a
given platform can support performance counters. However, besides
Win32/64, we support a number of other platforms. A feature at this
level should consider how the same functionality could be ported. It's
very helpful that you have a solid implementation for Win32/64 that we
can look at.
One concern about this implementation, though, is upgrade caveats. We
go the extra mile to make these easy and it seems that, even if very
well documented in your README, there are quite some pitfalls here.