This is just my not so expert opinion based on what I read.

IMO for modern compounds(with decent amounts of KE)shooting deer and just regular competitive target shooting....it's not that much an issue as long as you stay in the generally accepted ranges. 8-15%

A .89% FOC blows my mind and is almost to the point of having the back end swap with the front. Not good.

Now for lower KE setups and especially trad gear, it really seems to boost performance according to the studies. Without ever knowing anything about FOC, my compound hunting setups ended up in the 12-13% range. My setup for my trad bow is around 18%. My front end weight was just more to get the total arrow weight up, I let the FOC fall where it may.