DXMaximizedWindowedMode - that's an exact opposite of exclusive mode and clashes with Disable fullscreen optimizations checkbox.
As far as I can tell, these two apply only to Direct3D 9.
Exclusive fullscreen functionality has been removed from D3D8 since Win10 1809, need patched d3d8.dll from 1803 to restore it.
DXPrimaryEmulation shim in Compatibility Administrator with -DisableMaxWindowedMode parameter is still needed to restore real fullscreen mode for DirectDraw/Direct3D <= 7.
This maximized windowed mode implementation must be most complete Direct3D 9. You can still normally set gamma, use Game Bar and use Aero Peek to peek at the desktop on the monitor with the running game. You also see screen tearing when VSync is disabled in the game.