I purchased many, and I mean many, butcherblock slabs over the years for isolation on the Adona racks and on the floor, etc. I just put small rubber bumpers or equivalent Vibrapods between the steel and wood.
No heat build-up on my components, even the Coda at Class A runs cool to the touch. Over time I bought a bunch of the Shakti's and just throw them on for added absorption.
I'll tell you what fells, the biggest improvement I have every experienced is cabling. These JPS Aluminata cables have transformed my sound - eliminated electrical noise, increased bass output, and thrown the soundstage outside the speakers. Simply the best sound I have ever had. I'm looking for another Aluminata power cable as we speak.