RE: Wing spoilers vs. ailerons??P-61 Black Widow had spoilers....
For full scale, high wing aircraft, how is the pilot going to pre-flight inspect spoilers on top of the wing? In the end, they wouldn't. Eventually some family members would be calling lawyers instead.
I remember a bird-like glider design and build in one of the magazines that had very little vertical tail surface. To avoid severe adverse yaw when rolling, the designer used spoilers instead.
Bedford