I know this sounds like a joke, but I never did much tuning on Mac to get compatible games working yet did tuning for Photoshop and such. They tended to either run or not. I think it was because in that era (mid 90s) PC gaming was still heavily DOS based while the Mac was comparatively like a console: Limited hardware, the OS had some stuff for graphics, standard sound, etc.
On the other hand, Photoshop tuning was voodoo. Mac OS Classic offered a friendly-ish way to set the memory partition for an application, and hard-core Photoshop users would massage this by trying to have twice what they needed. You could also get in a weird situation alter on where Photoshop had a ‘scratch disk’ that was basically internal virtual memory, then the OS might be running either OS or 3rd party virtual memory, which was a predictable mess. Oh, and if you wanted to be super-cool you’d run Photoshop from a Ram Disk (so it was effectively all in memory already).