Why not use a hard plastic/rubber O Ring? It Seems like if you tighten the forend down enough you smoosh the soft one enough to nuetralize it's effect. That would float the barrel much better. I'll try maybe an 1/8" hard O Ring with the soft one that I've got already(+1/16") and sandwich it it for a1/8" float. I might even wedge the 1/8" hard ring just a little so that the forend makes a better union with the reciever.
This is basically what a guy here did with bedding compound. He ultimately made a perfect pillar around the lame one that bedded against the lug nut, its plate, and about a 1/2" in front/back of it against the barrel. The lub nut was completely molded into the bedding. Pretty sweet but if this works out ok I guess it's like the the lazy version of his concept.