Contact with the barrel, if it is consistent, may not affect the accuracy of the barrel but in general contact should be avoided if it possibly can be. The Garand and M14/M1A are capable of very good accuracy, and they have barrel contact. But in match configurations steps are taken to make the contact consistent and repeatable.
I don't see how it can be said that contact doesn't interfere with accuracy but is a detriment to precision unless he's saying that the SPS T isn't accurate enough to be thought of as a precision rifle. If that is the case, I've seen a few too many SPS Ts that are well within the realm of precision to believe that statement. The problem with the Overmold stock is that if you rest the foreend on a pack, the pressure/contact will be different than on a wall or tree limb, and different than on a pod. When you're shooting from a pod, the pressure will vary depending on the amount of cant, up or downhill slope, contour of the ground, etc.
Even with the poor OEM stock, the SPS T is still capable of very good accuracy in most cases and it may not be worth every shooter changing them out. I've seen some bone stock SPS Ts shoot well even with the Overmold. For myself, I wanted to eliminate the play in the stock and go with something that was more solid and consistent.
It may be that the pads are needed with that odd triangular barrel, I don't know. I would think that if pads helped the accuracy across the board Big Green would be slapping pads on the M24, the PSS, the 40, and all their other high-end rifles. However that is not the case. Pads where you describe are likely to prevent inconsistent stock pressure on the barrel, so I can understand that being used with heavy barrels and stocks that are more prone to flexing and those pads (because of their positioning and composition) provide repeatable conditions and eliminate incosistent pressure by isolating the barrel.
As for the palm swell, it is the one thing I miss with my SPS T. I really like the compactness of the LTR with the short barrel, but I would really like to find a PSS stock to put on it.