Ecole.dsk does need the r52 reset instruction AND a RAM write when writing in ROM (RAM is beside ROM, hard to emulate with asynchronous RAM, MiST does use a hacked synchronous RAM done for that), but not all screen is displayed, music is OK in MiST.
A lot of demos don't pass, in fact I didn't find one that pass damn in NEXYS4 FPGAmstrad's version. 50% of [http://cpcrulez.fr/Scene_Demos/index.php CPCRULES demos ] are running in MiST FPGAmstrad's version (a lot of not passing ones are using the double-buffer VRAM that needs more than 16Ko). I do
Others bugs are about dsk format, in fact a dsk is uncompressed into RAM at startup, so all dsk access are direct: