Initially I would say your not the best candidate. However, you state no ventilation on planing, this is key. What direction are you turning the propellers?

There are specific Labbing processes that can aid in gaining top end with your rig besides the diffuser removal. Are the propellers Labbed? Those methods are equally or more important than the diffuser.

BBlades- I am turning the props out. I have heard that turning them in may give me a little more on the top end but will hurt me around the docks. I'm in a lot of conjested areas when docking so thats not a good option.
I am planning on having the props labbed anyway. I was just wondering if I should consider the ring removal when I get the props labbed.
Thanks-

Out rotation can create more ventilation issues. Because the props are deep, the chance of small additional top end gains from diffuser removal are there due to drag. The gains could be larger on your deep V if you were surfacing the props.

If you have the exhaust passage capped the planing is effortless, I'd do it.