I put two layers of masking tape on the sides, front and bottom of the recoil lug when I bed a rifle. Afterwards, I further relieve the bottom and front. One of the reasons is to assure that if, when reassembling the rifle, any particles get into the slot, they won't cause the action to rock on the shield. I've seen that happen and the rifle won't shoot.
Pillar-bedding minimizes the tendency for the action to rock on the recoil shield, but I want to make sure extra sure it doesn't happen. It's more important to create the clearance when no pillars are used, especially with wood stocks.