10th gen i5(? might be another gen I forget, will check at home), 16GB RAM, RTX 2060ti, Win10

Could you be a bit more specific regarding that CPU? That's a very wide range.

i5-9400f, and I was wrong about GPU, it's 1660ti

It's really surprising then that you had such a bad experience with PS3 emulation specifically at least, the i5 9400F was a go-to recommendation there for a very long time, basically ever since that processor's release (6 years ago).

It was in last August they bumped their system requirements to the i5 10400F. Nearly all of the games marked "Playable" in their compatibility list should be plug-and-play territory, with mint performance.

What were the games you tested with classified as? Did you try to seek help on their community space(s)?

I didn't try reaching out, I just wanted to play Shrek Forever After (for a very random reason) and gave up after 5 minutes of choppiness. Like I said, there's probably a fix, and I appreciate that there's community support, but I simply didn't have time. Especially because on the PS3 side, this was after waiting a while for RPCS3 to do its pre-run caching.

Given that game has been marked "Playable" years before your CPU has seen its initial release, and that there are no notes on its Wiki page, I'd expect it to run essentially perfectly out-of-the-box, short of some regression causing issues.

You should give it a retry sometime if you can / want to. That said, I should probably let you know that the community can be slightly hostile, and they will ask you do the legwork if it's not a misconfig but a suspected regression (they'll want you to bisect the build where the choppiness appeared). You'll also want to run the topic by the volunteers in the #help channel on their Discord before opening an issue ticket on GitHub, as their GitHub issue tickets are not for support, only for actual issue / feature request tracking.