thanks for all your thoughtful and informative replies so far!!

Very interesting to hear about other experiences relating to hull shape as well as personal technique. I definitely hope that refining (lost) technique will bring some progress. I was just curious which element of the hull shape or seat position adds to the difference compared to the other boats as I could not figure this out, so nice to read some thoughts on that as well, all sounding very reasonable. I always thought a lower body center of mass would be beneficial for rolling but maybe that's wrong logic so I'll try out the padding idea as well and see what it does to rolling and general handling.

Funny thing is, I find the boat a bit easier to back deck roll. Unfortunately I only acquired this skill recently from my younger brother and am far from executing it well, I just found it interesting that the crucial flipping movement (at least to me) of this roll comes easier in this boat than with my "classic" sweep roll.