AeroPac..has used Coker pads
https://www.nar.org/wp-content/uploads/2014/05/AeroPacStyle-HPR-Pad-John-Coker.pdf for a long time. The rails have always had a "backing". They worked out great until Aerotech and others came out with hard hitting motors We began to have 1515 rail whip issues. It was not the rail or backing. It was the mount to the base that needed beefing up. We did that and have not had any problems with rail whip.
We use modified Coker pads at Spaceport America Cup. and have not had any problems with rail whip on up to 100 pound rockets.
A couple months back I helped Jim put his pad together. I helped for about 4 hours. Mostly lifting things that needed two guys to lift and adjust. Was/is his pad over kill? Nope! Not when the project weighs a couple hundred pounds and lifting off on a Q motor.
we all have different needs...when we talk about big rockets and large motors that means different things to different people.
Tony