Ok so I suppose I'll share my humble progress. Today I built the 2nd mock up of this just to get some idea of what I'm headed for in the target size (~42" I think). I was hoping to gain some insight without going all out in the build.
Here I have the 1st & 2nd mock builds. No earthshattering discoveries. I did confirm what I suspected that the larger I build the farther forward the CG shifts due to the building materials and added structure. I'm thinking C-Pack motors will help with that as well. I think I'll be ordering them next Friday.
I have 2 months of geo-bach'ing with my better half in Spain so it's a good time to make progress.