Wow, nice discovery pcdoc_! 🙂 That’s indeed the registry key we are looking for! Good to see we have progress in this wish. Probably with this information we can find a more clean method of permanently enabling themes in Remote Desktop. Found out using Sysinternals Process Monitor that the registry key HKCUSoftwareMicrosoftWindowsCurrentVersionThemeManagerRemote is created by C:WindowsSystem32TSTheme.exe.
Maybe someone who knows how to dissasemble/patch this file can make a permanent solution for this. Anyway, I will take a look at this as soon as possible!
Thanks again for this information! 😉