My take on this is that a fully bedded barrel, action to end of foreend, with a snug fit, may help to promote uniform vibrations, and the bedder may see an improvement over the unbedded barrel.
The problem herein is such rifles so bedded all the way to the fore end tip will then have varying amounts of pressure against the fore end transmitted directly to the barrel. And the angle and force that pressure has won't always be the same. There's different amounts across all the shooting positions and that includes resting the fore end atop something when testing ammo from bench shooting. And fore ends bend from sling use, too.
The only way to have uniformly consistant barrel vibrations is to keep everything from touching it except the receiver where it's fit into. That means it's gotta be totally free floating all the way around it. With enough room to let the fore end bend from normal handling and not touch the barrel.
Would you expect to hit your target resting the barrel against a tree trunk or on a fence post when it's fired?