RE: No more ARF's for me
I recently assembled my second Ultra Stick Lite and contemplated following what another had done with his Ultra Stick making it a two piece wing by not gluing the spar joiner. After some thought, it occurred to me the pressure that would be pushing the spars away from the ribs and that force had to rely on the plywood box holding the spars from spreading. I opted not to do it... and glued the spar joiner in to make the wing a one piece, with the result that the spar joiner is now integral to the spars rather than allowed to be a force pushing the spars apart.
One option for 4* builds then would be to glue a hardwood joiner in and make the wing one piece if such is manageable for transportation. I think doing so would strengthen the wing considerably.