Your observations going to the shorter Hypernut are the same observations I had going to the shorter 8.7 Sunova Flow:
Liabilities: I will catch fewer waves, I need to be on steeper parts of the wave and have later takeoffs closer to the shoulder, I will need more powerful waves, I will get less general glide when paddling and entering.
Rewards: narrower turning arcs, easier turning on the wave face, faster turnarounds when facing the wave, faster buoy turns, more fun and smoother turning in general after the wave is caught.
As stated, short choppy strokes to accelerate.
I think you can make these generalizations when you go to significantly shorter boards and reverse them when you go to significantly longer boards. Of course, board shape will also matter i.e. standard surf shape vs. long board type shape vs. tomo etc.
As a rule, standard surf shape i.e. tear drop point front, curved rails and narrow tail will be hardest entry, with long board shape and Tomo shape somewhat easier with more parallel rails.