I have a workflow where All statuses can transition to the Cancelled status

This Transition has a screen and properties etc.
However, I don't want users to be able to move from Done to Cancelled.
So to go from All to All except Done, I wanted to add the individual ones first, copy over the properties etc. Then remove the All transition when I'm sure I've done it correctly.
I can't change the global transition to a specific transition though, and I can't first add new transitions because Jira says they already exist. So the only way forward I see is deleting this transition first and then adding the new ones individually, but then I lose all my configuration.
Any tips on how to proceed?