I added a tiny hotfix so you can press space and drag to pan. Uploaded as version 1.0.1 now so if you download that and run the installer, it should work.
Fedora 44 with Gnome 50 on a Framework 12 laptop.
I figured out the problem though. I had the "disable touchpad while typing" setting toggled, and of course, it registers the holding-down of spacebar as "typing" and dutifully disables the touchpad. If I untoggle that setting, it works.
Might be worth finding a way around it. I imagine that's a popular setting to have activated.