Ofnuts should be of a good help, he has a cat.
More seriously, I would close the xcf WITHOUT saving it then re-open it, OK I would lose a bit of recent work like the previous 15-20mn, but at least I won't pass 10 hours changing fonts...
In all case I found your explanations a bit confuse, like what do you call "out of sync"? please give some screenshots with the problem and the tools' options and dialogs visible in the screenshots, and a more detailed explanations about the problem
More seriously, I would close the xcf WITHOUT saving it then re-open it, OK I would lose a bit of recent work like the previous 15-20mn, but at least I won't pass 10 hours changing fonts...
In all case I found your explanations a bit confuse, like what do you call "out of sync"? please give some screenshots with the problem and the tools' options and dialogs visible in the screenshots, and a more detailed explanations about the problem