Perceived shortcomings in a response to informal reps carry relative little weight in this procedure (in fact the regs don't even require a written response), it's the response to formal reps which is mandated.
So, if you highlight their response in formal reps then IMO you invite them to cover their tracks and their backs in their response. And if you don't and the same shortcomings are not apparent in any NOR then an adjudicator won't attach much weight to an argument you advance in an appeal which wasn't advanced in formal reps.
So you'd have to include in formal reps and hope they just dismiss/pooh-pooh.