I suspected you weren't building based on your lack of interest (perceived on my part) towards in depth building projects in the past but I previously didn't say it as to not take any wind out of your sails if that was the case.
I looked into doing a build myself but decided it's not very practical to try to build a pop-up myself. There's a reason 95% of home built campers you see out there are hard-sided: way easier to build.
However I can tell you that I was leaning towards having an aluminum frame fabricated and attaching Nida-Core panels to the frame.