I have gotten a 900gr arrow with EFOC using a Bloodline 330 with a 17'' 2117 footing on it, a 75gr brass insert and a 300gr head.
I found that the footing initally acted to weaken the arrow, like more point weight would. As it got longer though it added stiffness to the shaft. I tuned the shaft by adjusting the footing length.
As proof of this concept, the finished shaft had a AMO deflection of .175'' but it flew fine from a 70# longbow.
Something for you to monkey around with, having a footing that long makes a really tough arrow that acts almost like it's a tapered shaft.