I think some of the greatest wear on the bolt occurs on opening when it is natural to let the weight of the barrels press on the bolt as it is withdrawn. I often forget and find myself actually pressing down on the barrels as I turn the lever. That's when I can feel and sometimes hear the surfaces dragging--and wearing. I don't worry about it when hunting but other times try to remember to hold the barrels tight to the action until the bolt is clear and then let the barrels drop. Seems to me this simple act would virtually eliminate bolt wear.
Whilst I can see the reasoning behind this, if it was a significant issue, then self opening guns would wear much more quickly. I don't believe this to be the case.
Having a little smear of grease on the sliding parts should minimise any wear.