I took some stabs this morning at scaling...
The primary structure is cut from 18mm ply (.708"), and the driving factor for scaling this project is the slot/pocket width where tabs slide through to create the interlocked structure. I took a quick look at scaling to standard 0.5" and 0.375" play that one could easily acquire from the local big box store.
I also looked at the largest part span based on the best case diagonal span of an XXL (a theoretical 46.67" using a 33" x 33" cutting area).
Unfortunately, with 0.5" ply (a 70% reduction), the span of a "D Section Ring" exceeds the 46.67 part span (this pic shows a 12" grid):
Using .375" ply looks doable, however one ends up with a 53% scale of the original (a hobbit grow room). I'm gonna try a couple scaled pocket cuts tonight and do some further analysis.