IIRC, the ANSIWin10 setting is only used by TCMD to know whether to inject the ANSI64/ANSI32 DLL. The regular ANSI setting is used to turn ANSI on or off.
I believe TCC automatically uses Win10 ANSI when ANSI is enabled. I can't remember if Rex fixed the issue I was seeing during the alphas/betas. Or if it came down to having the settings correct.
I do know that if TCMD is started with the Win10 feature off, it will load the DLL. And even if you subsequently check that box, it does not get unloaded until you restart TCMD.
On my Win10 PC, I have ANSI=Yes and ANSIWin10=Yes, in both 4NT and TakeCommand sections of the INI file. And ANSI works correctly for me.