The spitfire 960 was my 2nd foil after my beginner bsc1060, it was a great transition foil, easy, mellow and nailed my jibes with it because it was much faster than the bsc.I still have it and its my light wind go to with a crazy short adv+ and skinny tail, still loads of fun.
the spitfires are awesome in choppy water, they handle turbulence so well imoWhen i first got the 960 I was running an ultrashort adv plus fuse with a 375 prog tail, I think moving the mast in relation to where you normall stand (or move yourself forward or back when you take off, might be the answer.
The short fuse will also stabilize everything, with regards to pitch (short is quite long in axis fuse speak)and yes any advanced foiler can ride your setup and tell you where to put the mast or whats the issue. you can overthink everything as a beginner because there are so many variables.