I jump all the time and here is my take on the issue, and I do ride alot in nasty chop and 20+ knots. First, not many people jump in 20+ knots nor do they venture out in those conditions. Even then, you are not keeled over that hard as you navigate swells and waves, you typically ride high and then when you see a wave you may be able to boost off of you then dip the board down slightly by engaging your lead hip and tack harder upwind to generate speed and pressure in the foil then explode off the wave. I can promise you a mast a little less than mine would not help me there b/c you just can't hold the edge over every wave in 20+ knots in non-flat water....you basically ride calmly then find your set and engage. I guess looking back critically I could agree b/c my foil is deeper in the water approaching a wave I have more energy and time to explode out, but it is negligible imho.
Obviously in flatter water, or for us here on a south 17knot wind the water is somewhat tame and you can then just ride leaning over and pick your moment. There are a few times I love the long mast for jumping, but typically the best boosts are in a controlled simple lean and progress into slamming weight into that lead hip and getting that board lower to the water before you let the foil explode for you with as much water as it can. Just my experience! Anything OTHER than jumping the longer the mast the happier I would be
All things considered the best boosting hydrofoil wing is a fast one that can accelerate quickly and then exit fast out of the water. The wing is more important than the mast length.