RE: Ultra Stick ARF Build issue
The wing on the US40 is very strong as designed.
Adding fiberglass tape on the joint certainly won't hurt anything but it does not need it if you use plenty of epoxy on the joiner and you get a good tight fit on the root ribs.
The plane flew with a TT46pro for a few months and then for three or four years with an OS 70 Surpass, the current owner has an OS 55AX on it which looks to my eye like the perfect match for the plane.
What is your plan for the aileron / flap setup ?