Just on the note of compressing games, for GameCube and Wii games you should use the RVZ format rather than the ones mentioned in the Reddit post. You can convert to RVZ in dolphin easily.
Dolphin Progress Report: May and June 2020
We've got a lot to get through the past two months. Headlining it all is that we're happy to announce support for a new compressed disc format developed specifically for Dolphin: RVZ. This lossless format allows for near top of the line game compression without compromising the integrity of ISOs,…
dolphin-emu.org
And for PS1 I'd recommend CHD, it usually compresses better than PBP and is supported by the PS1 emulators too.
