Lion is tricky because Firefox Dynasty isn't fully supported, but you're probably better of with Firefox Dynasty at this point since Chromium Legacy hasn't been updated in a while.
Fwiw I would encourage updating to Mavericks. I used to use a 2012 Macbook Air and Mavericks runs very well.
If you have a 2012 with 8GB's and are going to Mavericks, you might as well go all the way to Mojave. Disable MRT, MDS_stores, Report-crash, Spotlight indexing, software update (to prevent Catalina), and and carbon copy clone the installation (after it's fully updated) to an HFS+ (aka MacOS Extended-journaled ) partition with hdd and Fusion drives. (APFS should only ever be used with SSDs. )
Basilisk 2025.07.04 browser works very well in 10.7.5 Lion (11G63). I’m running this on my kiddos room white 2ghz C2D 17” iMac w/ 2gb 667 ram & original spinner.
If I was going to run Linux on this particular box, Id go with MX as Ive had fantastic, everything works out-of-the-box results with EI era macs. Yes, I will eventually get to replacing the spinner with an SSD 😀