Librewolf supports letterboxing as well, though the setting might be disabled by default

Agreed. That’s a really bold claim to make without citing (credible) sources

+1

…it was DNS

I’m running kubuntu on your same 2012 MBP. Runs great, but I’ve considered going pure Debian too, maybe still with KDE Plasma. You look happy; cool background!

My folks’ cats will eat that cardboard box. Seriously, they have to be really careful not to leave any boxes out.

I started using star names a long time ago and never had a reason to change (night sky - not Hollywood, though those are good choices too).