I am scratch building a small .15 size plane just because I have an engine sitting around. I like the look of the sig lil something extra and or the herr little extra (I think they are the same plane, both no longer available) however I though about making the wing with a wing tube more like the sig something extra 40 size plane. I looked at the building plans to the something extra and it looks like the wing has a straight leading edge and has a tapered trailing edge. The way the instruction read, it sounds like it has a constant wing depth (from top spar to bottom spar) for building ease. Perhaps I am wrong but the sheer web in the kit are 1.75 inches tall and the instruction only say to cut to width not hight so I am assuming that the spars are a constant 1.75 inches apart.

Questions:
1. Is this commonly done this way? 2. How will this affect aerodynamics (tip stalls, slow speed flying, ect.) to have a constant depth, tapered wing?