I did find this from Sixby and I respect Steve a lot so forget what I said since I am building hybrids and I would go with that Steve said.
"My personal experience is that I get more stability in radical large hook recurves using stabil core which is a combination of S glass and carbon fibers, next to my last center core and to the belly side of the bow. Between it and the belly glass would be a thin veneer, Usually .012 to .015 depending on the wood. I just take .015 out of the stack and usually hit close to my target weight.
As to UniWeft I have used a lot of it and what I have found is that I get the same of not more benefit from StabilCor plus its less than half the physical weight of Uni-Weft.
I have also placed the Stabil core dead center in the core and still do in some applications , depends on depth of stack and amount of laminations. My finding is that in longbows it is not nearly as important as it is in recurves as to placement. Still , If I get more stability closer to the belly in a rad recurve I can probably deduct that there is more stability with that placement with a D and R. In a straight longbow I doubt it makes any difference and the basic plus would be the light weight of the product.
God bless, Steve "