I don’t really see a convincing arguments for or against with Townshend applied to speakers, though I know they push hard for this in their marketing. Frankly, I’m not putting tall & heavy speakers on springs no matter what they say.
On my Yamaha NS5000 speakers the Townshend Podiums were an incredible addition. When I got them, I played my most heavy and dynamic music for about 10 hours to see if I heard anything different. On the first song I heard better bass. It was tighter and better than stock. I think that was the overall take away from my subjective analysis.
Now I was curious as to why, so I put my finger on the podiums. They were vibrating like crazy, and the speakers were NOT moving. For me that was good enough explanation that my ears were hearing the lack of movement in the speakers.
I have my audio gear about 25 feet away from the speakers (in another room), If I had them close to the speakers I would investigate more Podiums for the gear.
BTW - the only reason I got the Podiums was because the wife was complaining that the Yamaha's were damaging the floor with tiny indentations.