Amp Stands?

It's called resonance control and it's definitely not snakeoil. Resonance control is important in many different scientific fields, for example the popular Vibra-Plane platform was I believe originally designed to support electron microscopes, much more serious than audio, no? It stands to reason that it applies to audio as well.

Not to mention "Bass Suck' when you leave your speakers on the floor. I can't tell you how many times I have gone over to "non-audiophile" friends homes and after a short discussion we put their speakers up on a stack of quarters (4 or 5 under each corner) or small cups, even paper back books about an inch in, diagonally across the corners of the speaker works well.
They are "blown away" by "how much better my speakers now sound".
The next time I go over, they usually have gone out and bought some stands.

I have found the denser/harder materials (granite/stone/glass) to remove some tonal/harmonic color.Wood has always been my preference.Try the maple cutting boards available through TI MAXX.Relatively cheap to try .Sizes vary from store to store/week-week.
If you like the results,then you can work up to the more costly "signature" products of various manufacturers.

Since amps are electrical devices compared to speakers, the mechanical vibrations compared to the forces between electrons by the huge power of 10. Hense they can't alter the audio performanse of the amplifier.