So, if I understood correctly the bloom mechanism, even reissued 5* that I already got but don't want to dupe are worth getting, to be used for blooming?

Gaillardia was the first event girl I got after beginning the game, so I needed only 2 skill and 2 dress blooms, and at first I didn't intend to get the girl again (also, because current event takes lot to farm to get ampys)