I suspect that when you can lean way back you are lowering your center of gravity so that a strong hip snap is less important. Most paddlers have only a very weak hip snap while laying on the back deck, but a much stronger one when sitting upright.

You are correct in that the CLC boats tend to have high cockpit coamings that can make leaning back difficult. And your suspicion about raising the seat causing instability is also on the right track. A recessed coaming sounds like the way to go.

A rolling technique that doesn't require laying back (like a whitewater C-to-C) might be your best bet in the Chesapeakes.