Very interesting I wasn't aware. After glancing over that doc, it looks like they smuggle UTF-8 in through the -A variant windows APIs [1] by explicitly setting the CP_UTF8 codepage in an application manifest. I wonder if this actually uses UTF-8 internally to service the API call or if it just manually converts strings to wide form and calls the -W variant on the windows side instead of making you do it on the app side. If the latter it may be better to avoid this feature so you don't close the door on potential optimizations like I mentioned above.
[1]: Windows has two variants of many API calls with either -A or -W suffix, where the -A suffix is for strings formatted as 1-byte ASCII (or a specified codepage) and the -W suffix is for strings formatted as 2-byte UTF-16 (kinda). Example: DlgDirListA / DlgDirListW, https://docs.microsoft.com/en-us/windows/win32/api/winuser/n...
[1]: Windows has two variants of many API calls with either -A or -W suffix, where the -A suffix is for strings formatted as 1-byte ASCII (or a specified codepage) and the -W suffix is for strings formatted as 2-byte UTF-16 (kinda). Example: DlgDirListA / DlgDirListW, https://docs.microsoft.com/en-us/windows/win32/api/winuser/n...