MM,
In your previous thread where you asked about largest wing areas, I referred to a my largest 1/2A stunter, which I call the Spring Break Special, because that is when I built it during college. It has 201 in^2, with a 6-5/8" root, 6" tip and uses a solid LE and TE, no planking, 1/16" ribs spaced nominally on 2" centers. The covering sag is not that much, and it saved a ton of complexity and work. As you can imagine, I was in a hurry with only a week off.
On the other hand, I have an OPP (Other People's Plane) awaiting completion that is a bit smaller, but is basically constructed just like a Nobler wing, except the main gear is in the wing. The ribs are 1/32", as are the cap strips, the LE planking, and the upper and lower TE sheeting. The spars are 1/8" square. The ribs are spaced at 1" centers. It is not covered yet, so I don't know what the covering might do to it (Starved Horse) but it has no noticeable ripples in the finished planking. Tissue would not be a problem, but polyspan and dope might be. I believe you said you were not a fan of the Baby Pathfinder, so a "Mini-Nobler" would probably not be a fun exercise, either. But these wood sizes are suitable if you can work with something more fragile. I don't have a weight comparison with the Spring Break Special, so can't help there. But I'm sure the SBS survived a couple of crashes over grass while other guys tried it out, whereas the Baby Nobler construction might not.
Hope you keep chugging on this project. Will be interesting to see how it turns out....
Dave