I would find public / shared characters that aren’t very clearly marked as NPCs ‘puppeted’ by multiple people very strange.
I understand the benefits of having the ability to play well-known people in the setting (such as shop keepers, for instance) to provide a more realistic backdrop to other people sceneing. But I also think it is a proverbial minefield for people going “you’re playing that character wrong” or fights over who gets to puppet the public char for a specific event, etc etc.
This is “tread warily and discuss well” ground, I think.