I am a Stillpoints user.
Stillpoints recommends placing the Ultra SS or the more expensive Ultra 5’s under speakers first.
I ignored this and isolated first with Ultra Mini (least expensive) under the components, but not the amps. I then added Ultra SS under a pair of Focal 1038be I had at the time resting on carpet over concrete - the difference was not subtle, the sound became more controlled across the range, down side is it took 4 each, plus adapters between Stillpoints and the speaker.
At this time, I got in new amps and waiting for new speakers, costing 5X that of the Focal while still playing the Focals - it sounded very good, enough where I wish I pocketed the difference but addiction prevailed and the new speakers were on their way.
The new speakera were on manufacture spikes and I then tried Ansuz Dark DTC followed by Stillpoints Ultra SS - again realizing a more controlled sound emitting from the speaker. I will be moving to the Ultra 5s under the speakers as budget presents itself as the SS did their job and now can assume the 5’s will get me better than 5% more result. At 5% the purchase has to be in the buy, meaning a deal.
All other gear floats on Ultra SS, and soon 6 under the DAC and server, again the 6 need to be had at a deal.
Afternarket is such that it is an industry in to itself. Componet and Speaker companies leave these tweaks out as it’s a personal choice as they don’t know what the entire system looks like or the environment it resides in. Cost also becomes the factor, they would have to up charge 25% plus for manufacture and carrying costs. There are a lot of examples in auto, boats and even homes. Why does kitchens in new homes not include a SubZero refrigerator, it’s only $10K on a six figure house?
Isolation works, as does treatment and a solid power foundation - these items can help shape a moderately priced system into a great sounding system and stupid priced systems like I am running question the amount of money spent where I did not have to go all in so to speak even after following the disciplines of power, isolation and treatment. My falling off a few times to from the discipline resulted in buys of uber priced gear that sometimes I remorse of course until I hit play :-)