Well, i had several things (mostly games) work by changing these settings. Also in many non-game cases the program did work but it had visual glitches (a common

Well, i had several things (mostly games) work by changing these settings. Also in many non-game cases the program did work but it had visual glitches (a common issue with some older apps is when they draw directly to the screen - this is slow with regular compositing, but by enabling a pre-XP2 compatibility mode Windows seem to render the windows in a different way - i guess some canvas outside of DWM - that is faster to directly access for such programs, you can notice that these windows bypass the DWM decorations).