I guess that depends on what you mean by equivalence between CPS and SSA.

My prefered form is basic blocks with arguments. Where the final jump has parameters it passes to it's destination blocks.

That form has a 1-1 equivalence with SSA and I find it much easier to reason about. Every SSA algorithm I have looked at so far works just fine on the representation. Plus there is none of the annoying transforming into and out of SSA.

If you omit the mucking about with return closures in CPS what is left is basic blocks with arguments.

To see basic blocks with arguments as a form of SSA just see every basic block argument as a phi function, and the callers parameters that feed into that argument as the other end of the sources of the phi function.

Just from your description I think your pizlo special SSA is actually a form of basic blocks with arguments. What I don't see from your description is why Upsilon and phi aren't combined into a single notion (What I would call an incoming block parameter).