It used to back in the day, especially if you tried using shitty windows usb inkjets.

Nowadays basically all printers are network printers (they are, aren’t they?) plus we have cups which is the same thing macos uses (so manufacturers actually care).

(I assume you meant “I created a separated /var partition”)

You can move/resize partitions from basically any live usb (via cli or gparted for gnome and kde partition manager for kde).

Shall you want to, you can also merge the var partition with (say) your root partition:

1. mount both partitions in two directories (just create empty ones and mount on them, say ~/root and ~/var)
2. inside ~/root create the new var/ directory
3. copy the data over
4. edit ~/root/etc/fstab (remove the line for the old var partition)
5. use whatever partitioning tool to get rid of the actual partition and expand the previous/next one

Be aware that you can very easily lose your data ;)

PS: just in case, try running flatpak uninstall --unused