Is one single example in the world anytime from now to 2040 sufficient to resolve YES, or do you require a significant usage?

I implied something closer to your latter option; there are already some things that could be called proofs-of-concept, but they're mostly laying around there, not used in actual production code.
Well, I guess, a standartization of the algorithm would also suffice, as well as a single example of an application (desktop, mobile, AI, whatever) wherein the fractal compression is used for reasons besides its sheer novelty.
I guess I shall look around for proper protocol around here and amend the description later.