Hey JD, that's so cool that we both discovered that sweet spot!

I think the Iso-Cups are amazing under the Torii, and yes on stands or racks helps as well. I'm always fascinated by isolation and coupling and audio.
No, at present I can't use Iso-Cups under the CSP2+ because of logistics. Where I have the preamp if I use the Iso-Cups and the PS Audio Perfectwave AC-12 power cord that I love on this preamp it won't stay in place due to the weight and the backwards pull of the cord. I have it (and the ZP3) now on Tenderfeet, which is an improvement over the stock footers. But soon I'll have another set of the Ingress Audio Engineering "Rollerblocks" and I'm going to try those under the CSP2+ -- my experience with these under my HR-1s is very favorable.