Stillpoints - snake oil?

MY main strong point is DISTANCE. My audio equipment is away from the speakers, and the electronics mostly to my immediate left.
And the turntables even further back behind and to the left. So the TT are over ten feet away from the speakers.           
Only the amp is near the speakers. but behind an additional clear foot, and clear by two ft to each side. The amp sits on a 70 lb concrete patio slab
MY playback is typically at 50dB to 60dB. Though of late breaking in stuff I am up to 70dB a lot

the manufacturers do not want to include expensive isolation devices,  so that the customer can choose which brand/type, if any, they prefer...I like the Mapleshade maple boards and brass cones under my equipment...

same for power cords, fuses, cables, etc...

Do these manufacturers at least recommend the use of an expensive isolation device, cord, fuse , cable , etc.. in order to get the best sound from their devices? They can leave out specific brands if they feel uncomfortable recommending them but in at least a generic sense do they recommend one go out and purchase these things so their stuff will perform better? I'll email the maker of my amp and see what they recommend. They spent the R&D building the thing, I am not an engineer or designer of these things, I assume they know what they are doing so I'll trust their advice and if they say yes it will improve them then I can consider if I want to spend my money on them over a consumer proclaiming yeah I spent $5000 on tweeks and damn they work great!! 

I know some do...when I purchased my first Classe amp, the manual recommended an upgrade power cord...