I believe there's a few other models of LQG and others which can still be tested. But I'm skeptical we'll see any positive results. The only reason I hope I'm wrong is that if spacetime can't be quantized then we're stuck with singularities which aren't much fun all things considered.

Yeah I thought so too. AFAICT the standard model and general relativity are incompatible with any spacetime quantization larger than the Planck scale and that's very far outside of our testable range.

I seem to remember some discussion about this with GEO600 results a couple years back. Their detector was seeing a bunch of noise and the conversation included asking if we had begun to see granularity of spacetime at their resolution.

The end of the article states that everything it discussed prior is only part of a "toy". It is known that the toy being studied does not fully correspond to our universe.

Think of coming up with one of these theories like writing a complicated computer program. Sometimes the whole task is too big to even think about, it you sort of understand one part of it, so you work on getting that part sorted out as best you can, and hope you can somehow figure out the rest of the program later, and it'll be useful.

Sort of depends what the theory predicts, as to whether that's relevant.