If it shoots well and the action is bedded well, being synthetic the stock should be stabile and not need to be free floated. If it is not shooting up to expectations and everything else appears good - action bedding, screws correctly tightened, scope, mounts, etc. relieving the barrel channel might be the answer - just like a wood stock. Free floating often helps - but it isn't always the only answer as other conditions might be in play.
