Have to say the Townshend guy’s videos make an awful lot of sense. MC is making a lot of sense on this too. Slap your table on one of those platforms and I bet most problems go away - unless maybe your table’s sitting in a bass node/resonance/peak spot for your room? How much have you experimented with moving your rack’s position (I mean just a bit, not into a different room)?
I’ve been into high-end headphones for a while and they’re wonderful but they can’t match nor eclipse a great speaker/vinyl system IMO. The problem is dealing with room acoustics and vibration feedback. When I had a SOTA Star/Nova table (built-in spring suspension tuned exactly for itself), the vibration feedback into it was literally never any worry. Things got a LOT harder when I got a Clearaudio table. But still, I found I didn’t have any airborne feedback issues of note, even with my HUGE Canterbury speakers played loud, once the ground & structure borne vibration was addressed via rack/etc. Then again I also don’t have 3 subs (I know they are supposed to smooth out bass nodes, not make them worse)!