Comment by 3r7j6qzi9jvnve

If it helps, I run ff in systemd-run with memory limits set -- that's usually enough to avoid the problem in the first place (ff does freeze when loading google spreadsheets or whatever heavy UI, so I also have a script to adjust /sys/fs/cgroup/user.slice/user-1000.slice/[email protected]/app.slice/ff-*.scope/memory.max and memory.high at runtime... I should publish my $bindir someday)

    systemd-run --user --scope --unit=ff-$$.scope \
     -p MemoryMax=4G -p MemoryHigh=3G \
     -p MemorySwapMax=0 \
     firejail firefox "$@"