I'm aware of it, but it's awkward to use in practice. You have to track down all the FF processes, each time you run it, and adjust all their scores.
Ah. Yes, that is awkward. Well, nonetheless, you taught me a new feature. Thanks!
sounds like a job for a program
Maybe firefox could self-adjust, as a policy?
You could launch it as a systemd user target with OOMScoreAdjust=500 in the service section; weird and unconventional but wrapped in .desktop file it doesn't appear to be unwieldy.