I've got it kind of working using Sikarugir on an M1 mac using Tahoe 26.3.1
I also got it working using Crossover, using all the old steps to install titanium, patching it for P99, etc, but the performance was pretty bad and I don't want to pay for crossover.
For Sikarugir, I followed the steps exactly to first get Steam running using this guide:
https://www.youtube.com/watch?v=LZgaBTcHEwc . Then, I copied the everquest/Project 1999 folder I was using from crossover into the sikuragir wrapper, selected eggame.exe, added the patchme outside of the quotes, and it worked!
Issues I'm still having are 1) the game often crashes once I close the game and try to re-open. I've had luck restarting my computer to get the game back up but it's not a sure thing. and 2) horribly slow loading times