Are you planning to reuse the factory turn signal or a universal 8mm threaded turn signal?
Mirror block off is done, working on a version with turn signal but I refuse to have exposed bolts on the block off body like the other guys so it needs more massaging currently. But I will have something soon
I know this is a Ducati Forum, but I would give my left nut for mirror block off indicators like you describe for my MV F3.