I think they work through by going by the rom name and then checking the database online. I don’t know if romHacks work, it really depends if the community added it. You have to make a (free) account on the website to track your achievements and link to your emulator. Some emulators work with it, some don’t. But I haven’t dug deep on my retropie/retroarch devices to know if they all work.

I have nes->psx on this device so I’ll be testing a lot tonight.

I know delta and PPSSPP in iOS have support for it, but Delta requires a patreon subscription to use achievements so I won’t be doing that.