I might be going against the grain, but I'd say if you won't have to go out of you're way to do it, go ahead and slip a washer or o-ring onto the forend stud.
I don't think anyone has ever reported worse accuracy after doing this, but a huge number of people have reported better accuracy.
Basically, the worst thing that happens if you add the o-ring / washer, but later find it wasn't necessary, is you go to the range and enjoy the gun anyways. The worst thing that happens if you don't add the o-ring when it could have used that mod is you waste a whole range trip flinging lead all over the place, not to mention like $20 or $30 or $40 worth of ammo, and end up with a negative experience instead of a positive one.
Adding a washer under my forend stud took my .308 from an ~8-10MOA shooter to a <2moa shooter (and I'm not that good, nor have I shot from an actual rest).