If I got the Townsend Platforms, would I remove my steel plate and sit it on their steel plate?
I wouldn't as the outriggers provide lateral stability for the Reference 5. The podiums only have a small amount of lateral movement, but I'd feel better knowing the speakers had their designed lateral support if someone (somehow) crashes into them. The podiums don't have any provision for bolting down speakers.
I'm a big fan of the Townshend podiums, I tried the Gaia prior to getting the podiums but returned them (disclosure, I didn't have both at the same time for a contemporaneous assessment).