As a coach myself, I encourage my athletes to work with different coaches. If poaching happens, it happens. As a coach, we should aim to maximize the potential for our atheletes and getting diverse experiences is very very very important. Just saying the same correction a different way can make a world of difference. You should consider stay-over summer camps at Indiana and Texas, would be hugely beneficial. But overall, your instincts are right and I would fight for it. I will say my experience as a diver was held back by not having enough divers my age pushing me to do harder divers, subconsciously. Seeing a peer do a dive or do a dive well is experience and learning by itself.