Hello,
With Moses we were able to test the exact same Hidrofoil (wing, stabilizer and fuselage) with 3 different mast lengths, 91, 101 and 111, and the diference its huge!
We used the Sport setup 558 wind and 330 stabilizer, which is something in the middle performance wise, not too fast, not too slow.
The 3 riders testing it had the exact same opinion:
91 mast - Direct feeling, very sensible to foot position, board turns easier and there less roll resistance
101 mast - Some delay on the inputs, foot position less important, board harder to turn and more roll resistance
111 mast - Big delay on the inputs, board seems to track in the same direction regardless of what you do, much harder to turn, huge roll resistance, much easier to move your feet around in the board.
So with the increment of mast lenght you lose maneuverability but gain stability, it was interesting for me as i didnt know this.