You are a step or more than a few ahead of me with the vid to express your thoughts. I have often struggled to clearly get an idea across on build threads.
Good to know that the S.S does roll nicely. Even my little Kadet Jr seems to roll reasonably well. just an observation from flying it. It has the dihedral reduce by half and strip ailerons added.
Oh on the wing to saddle gap. I will fix that. Likely with epoxy and micro balloons. Will make a thick past and with scotch tape on the wing mating surface just mush em together. When using a thick mix of epoxy and micro balloons I like to apply some normal epoxy and then the paste. That gives good adhesion. The paste will be applied to the wing saddles. Should give a perfect mate. Iv'e done that before. Once the paste has set real good then I carve off the squish out to get a true flat surface on the side of it.
Back in the 60's 70's there was a 2 part epoxy paste that did the job of the micro balloons epoxy paste. Brown if I recall correctly. Heavy, could be smoothed out with a wet finger. Can't recall what it was.
Bondo might also be an option, not sure. Iv'e never used it before.
Ken