So while working on a checkout today, I absentmindedly got myself stuck in an odd place...
Cue list 1/ executes 12/, Cue 12/828 has a macro that sends a [Goto Q 1/828]. I hit the go on 1/828 and get stuck in a loop where 1/828 fires 12/828 fires 1/828 ad infinitum. Realizing my mistake I figure I'll just release list 12/, but that doesn't work. So I head to the cue list index and delete list 12/ which stops the loop, but also seems to have cleared my undo list...
Not a situation I think I'll find myself in much, but annoying to have lost my undo list all the same.