Yeah, me too. I haven't settled it yet and I'm holding release under after 7.57 so I can add the device checks. Once I pick something though, I'm stuck with it unless I want to have to explain to users to manually edit their data. / is a popular separator in names. + is probably too. I thought of ¬ but that might not be on every keyboard and looks quite odd. ; maybe, = or ~ maybe. Hmmm, these are the tough choices
One thought was to make it configurable - but I'd rather not add another setting, and it might make troubleshooting harder.
I'll try the str.replace. I haven't tried to tune the code much. I can see there's a bulk update for calibre fields I'll need to test - right now I update the full collection list id by id so I'd have to change it to update the list of ids collection by collection.