My OS, since I installed Earlyoom, is rock solid.
To be fair, it was rock solid before.
I don't think earlyoom will help if the tmpfs fills up.
As long as there is enough free ram,
it doesn't care if the tmpfs is out of space.
earlyoom can keep a logfile showing what it kills and when and why.
If you can delete enough files to get enough space, you should be able to shutdown gracefully.
I still wonder if clicking the save button flushes the tmpfs or not
or just copies to the save file/folder.
Just run this (sizes of dirs in tmpfs)
du -h /initrd/mnt/tmpfs/ | sort -hk1
or this: (sizes of files and dirs in tmpfs)
du -ah /initrd/mnt/tmpfs/ | sort -hk1
Run before and after clicking Save
If the Save button deletes most of the files in tmpfs,
that gives you more working space.
But I suspect it just copies to the save file
and does not clean the tmpfs at all.