I'll second that STL will make FNV work on Mint, I've made many comments extolling how much better it runs that way than it ever did on windows

that being said RED ALERT:

You need a version of YAD not from the stone age (so not the distro software manager version) to install STL. The instructions for making your own YAD from the GitHub assume you've done it before and can understand what phrases like "do the usual" mean. It's not hard but it took me 45 fucking minutes to find a comment 5 months ago on Reddit that said "do this exact command" and made it all go smooth. If you're familiar with GitHub and the make command: you're good homie.

If you have any issues with FNV you can PM me as I finished my playthrough recently and did everything you can do in modding to it, LoD and all, no issues. Ok, that's a lie, but the issues were my fault, not the system.