Not sure if these are any good or even suitable.
I have two sets of Sounddeadsteel squares which I have used under speakers and stands for years. No longer use them so you are welcome to have them if you want to experiment - make a forum donation if you keep them or offer them back up with the same proviso.
One side is heavily scratched up but the other is fairly clean and I don’t see any obvious reason why they can’t be used either way.
The newer Sounddampedsteel squares which I use under my equipment rack have a non slip rubbery coating on one side so can only be used one way round.
Welcome back!
Wayne will have those off you as hipster coasters.
Cheers Paul (good to see you back too).
As it happens a solution is winging its way to me but very much appreciate the kind offer. Perhaps another meatman might want to take advantage?