After having to troubleshoot old La-Mulana, I've come with a new idea:
A hack for old, classic La-Mulana that GREATLY diminishes the hassle in getting it to work properly in Windows 10, use Borderless Windowed, and add Options to the main menu as well as an external configuration tool.
And perhaps to fix the Boss Rush map so it can be loaded with the translation.
And for something else:
A patch for the Maze of Galious remake fan-game by Jorito (Brain Games?) to make it start windowed rather than full screen.