OP here - really it’s just a matter of I found a cool thing and wanted others ideas/input. I never had a pretense of a proof or a formalization just a cool pattern that emerges from folding the Ulam Spiral up a certain way. I think we were over zealous in the gcd triangle being an exact correspondence now as it clearly is not for some cells.
The pattern does not exactly match GCD as it turns out - but that makes it more curious actually. Here is the Mathematica code that does work for other values.
