Here are my thoughts .....

I wasn't a heavy FOC believer until this year and now? I have 100 gr brass inserts and 160 gr broadheads for a total of 160 gr up front. I shoot carbons - and the ball and string theory seems to work (that is, throw a ball with a string tied to it, and the string will follow the heavier ball)

As for planing, thats broadhead design IMO. With the speeds of recurves/longbows, if your arrows are tuned, I doubt planing will be much of an issue ever