re: Help pls! How do I secure a diamante brooch to extra large gumpaste bows?

the brooch is meant to be the center of a large gumpaste bow so I doubt the cured, hardened hot glue would ever touch the cake. If it concerns you (or the OP), cut a small wax/parchment paper circle and lay it on top of the hot glue as it dries. I haven’t seen the brooch in question or weighed it, but they can be pretty heavy. Royal might hold it, I would test it good first.