I've never really chased the high FOC thing, cannot get it with the heavy wood shafts I use anyway, but I certainly don't dis-credit it though. If you want to go for more FOC, go for it. It certainly sounds like it has merit, and who am I to say what's right or wrong for someone else.
I shoot heavy up front, like 190 grains minimum, on heavy wooden shafts, typically with an all-up arrow weight of 750-850 grains, often more. I have only ever really chased as close to perfect arrow tune as I can get, with good stout cut-on-contact broadheads. Full penetration or pass-throughs are normal for my set-ups.
Spine calculators always seem to tell me I'm either too weak, or too stiff, but the consistent excellent arrow flight I'm actually getting tells me I'm spot-on, so me personally, I don't take too much notice of these calculators. Good for finding a place to start, but actual shooting and tuning to the results of that shooting trumps a spine calculator guess-timate.
For me anyway, if it flys really good, then it must be really good I reckon.
My advice is, if you are happy with your arrrow flight, it sounds like it's time to sharpen up your broadheads and go hunting
Best
Lex