You can now switch the mouse cursor on and off in the Settings UI of Rune 0.5b. You need to enable the local browser to see this control.
You will first need to update 0.5b to patch-level 7 with a git pull. This can be done without accessing the command line interface.
PS @wiskinr, I needed to borrow an anorak to get it all working, so you won't need one.