Thanks!! 😻 I pushed a merge with main, resolving the conflict in tests/libcxx/expected_results.txt by enabling the tests for this feature, then I updated comments/messages to address @barcharcraz's feedback, and finally nitpicky feedback of my own.

I'm mirroring this to the MSVC-internal repo - please notify me if any further changes are pushed.

Thanks for implementing this "I can't believe it's not a DR" feature! 😹 😻 😸

Thanks for bumping __cpp_lib_format to its final value in C++20 mode, which indicates a date later than the "finalization of C++20“ by 38 months!