I do remember Peter Belt and all the crazy devices and claims.
I have a few things from Herbies I use and change out
according to the rack, floor situation and equipment
at the time. All work very well and add a bit of a different flavor to the sound. Herbies Supersonic Tube Dampeners on all tubes. Some equipment is more responsive to these changes.
I also have carbon graphite cones from the past that worked excellent on an Audible Ilusions M3 I used to have and a later MFA Magus 3B Pre. These were used on a Target shelf with Maple shelving.
Currently using the isolation vibration pads rubber/cork/rubber they work very well on my glass shelf rack.
None of these ever very expensive, there is no need to spend a lot.
What is nice is a lot of this can be DIY.
I don't know what any of this would do to ICE amps.
Do one piece of equipment at a time.
Let us know how you make out and any changes you hear.
I do know what you mean with "unhealthy yearnings" there always seems to be more there to be extracted from the system. I get bored too and can't leave well enough alone which most of the time translates to some kind of dollars involved. That IS the sickness.
D