Would a small standalone example (or more) be a good idea? I just wrote one at https://github.com/scikit-build/scikit-build-sample-projects/pull/50/files, which does a simple pi calculation in pure Python and with a C extension (with a little C++ for the random number generator) and a scikit-build-core build. Doing so was a bit tricky, as docs are currently scattered or in PEPs (multiphase initialization seems to be mostly in it's PEP). I figured out some of it looking at the modules in CPython.