It looks like you have an interesting experience with SFR's mounts. I purchased theirs & their transmission mount in 2021 and I get a lot of vibration in the cabin. That's why I'm here researching. Isn't rubber supposed to absorb more than polyurethane? As I read here, it seems that the rubber mounts are absorbing the vibrations better.I had a MORE mount break in half and put my engine into my radiator.
I've had Brown Dog destroy the bushings (both rubber and poly) in 100 trail miles.
I'll only run SFR now. And since he's having his own custom poly bushings poured, they dampen vibes better than the MORE or Brown Dog did.