Rosiehigh frequency isn't inherently wrong, it depends what your overall routine looks like.
I wouldn't recommend actual core exercises daily, but I do them nearly every training day. i refrain from doing them on days before any heavy full body compounds like squats or RDLs.
imo just toss them on a leg day twice a week
i do abs on arm/chest days like today was chest day then wed is deadlift day i could not do them on leg days because my glutes legs hips etc are all impacted already from the heavy lifting of deadlifts
