is there a way to disable DWM on Windows 10 1903+?

In W10 you can do this easily, even though it doesn't show in any settings. The ability is still there, but you have to do it via registry.

The easiest way is to first do a manual adjustment to the program you want to use, using the compatibility tab. For instance, change it to Run as Admin.

Once this has been done, find the setting in registry, looking at

[HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers].

Find your program, add DISABLEDWM to the data listed under the program, remove the RUNASADMIN and away you go.

This method is still working for me on 1909.