Even if this Thread is older here are a few observations I found:
Setting WINSRV03SP1 under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers or the HKCU equivalent did work for 32 Bit applications and reported 5.2.3790 SP1 even on Windows 11. What it didn't do was set the basic theme unlike Windows XP compat mode (idk if the one from Win 7 does this already because there you still have DisableDWM).
The sad thing is, it doesn't work on 64 Bit exe files, the way is to add the EXE file to Application Verifier and check Compatibility and HighVersionLie, then right click and click Properties and set the following:
Major: 5 Minor: 2 Build: 3790 Service Pack Major: 2 Service Pack Minor: 0 Suite Mask: 256 Product Type: 1 CSD Version: Service Pack 2 (or the Service Pack you want)
Further interesting observation is, that all compat modes that got removed from the UI, still work in recent Win Versions so setting in HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers:
NT4SP5
WIN2000
WINSRV03SP1 as already mentioned
WINSRV08SP1
do still report the right version.
Also interesting setting DISABLETHEMES in Win8 or higher does either disable Themes for all controls or if you set a compat mode which disables DWM composition (e.g. XP) then it does turn into full classic.
For the 64 Bit Version Lie (over Application Verifier) there's a little downside, that it does only override the Win32 GetVersion(Ex) and not the NTDLL RtlGetVersion, and also does not change the output you get from the registry.
I also tried Compat Administrator setting the VersionLie here without success for 64 Bit App.
What is intresting in Compat Administrator, that there are way more Versionlies aviable which could be used.