Those are straight garbage. Absolute trash. It’s not a question of whether or not they will crack, it is only a question of when. There’s not enough cast material there to provide the strength needed to support those studs.
Adapters are perfectly safe if they’re made of the proper material and are thick enough to put enough of that material around the studs. In general, if you’re looking at aluminum spacers they should be billet and at minimum about 3/4” thick.