Richie,
I don't know much about carbon arrows but have started using them during last season. What I have found is that with my gorilla draw of almost 32" I can't point weigh my CE heritage 350's nearly as much as I'd like. 100gr brass inserts and 125 heads are actually a little weak with a 32 1/4" cut shaft. I've been wanting to get up into the 160 or 190 range for head weight but can't.
However, I was recently reading a post here about EFOC and a couple comments were made about Doc Ashby's internal wood footings and how you had to be careful not to glue the whole internal footing inside the shaft or IT MAKES THEM TOO STIFF.
That last part caught my attention....
There may be a way to use lighter, weaker spined arrows and basically "shorten them internally" and get the higher FOC's people want. I believe the theory is that when you glue the dowel inside the shaft, it stiffens it so much up front that the working portion of the shaft is quite effectively shortened and the results are about the same as if you'd shortened the shaft physically.
Again, just hearsay from my perspective at this point but it makes sense to me. I believe it's Clay Walker's post that started that particular thread so you could search his name to see the exact comments I'm talking about.