Everquest finally upgraded their client to use 64bit. On Test Server this has already been pushed - so today i used a nightlybuild (Version 2120220105 (21.1.0.33885)) and created a 64bit Windows 10 bottle (would not work in the default windows 7 bottle).
So installed EQ from scratch, copied over my old Everquest folder so i didn't have to download the 10+ GB in size and the game works fine.
No excessive loading time, no hickups, no gfx glitches or anything.
This was tested on M1 Macbook Air with 8 GB.
Also tested the new 64bit client on a Intel Macbook Pro - had to change the bottle to Windows10 64bit again but works great otherwise.