You really don't want flaperons on a Shoestring.

Normally flaps are inboard on the wing. Ailerons are outboard on the wing.

When flaps are lowered, because they are inboard, they create sort of washout on that wing. Washout helps avoid tip stalling. That's a good thing to help avoid on landing. Since the ailerons are outboard, if they were to deflect downward, they would actually create washin on that wing. Washin often causes tip stalling.

Do yourself a favor and do not setup that Shoestring's ailerons to act as flaperons. You really don't want to do it.