Hi, I noticed a striking similarity between the collation versions reported by Windows and ICU, and found my way to this new system copy of ICU (C APIs only) that you can use on recent enough Windows[1]. Not planning to do anything with that observation myself but it seemed interesting enough to share...
[1] https://docs.microsoft.com/en-us/windows/win32/intl/international-components-for-unicode--icu-