I was actually trying to increase it, by shrinking the windows partition. It feels like Universal Blue is a little weird in its handling of grub, and from what I understand, I wasn’t supposed to be dual-booting it on the same disk to begin with.
Edit: But yes, I take full responsibility for that blunder.
I managed to destroy my immutable linux install by resizing the OS partition while it was running.
Doesn’t Firefox offload unused tabs by now?