Mike Rapoport wrote:

Spoilers function the same as ailerons at low angles of attack and better
than ailerons at high angle of attack. The primary advantage of spoilers
instead of ailerons is that it enables full span flaps. Spoilers also
reduce or eliminate adverse yaw.

I assume there must be some disadvantages of spoilers for roll control
as you see them so rarely. What are the drawbacks? Cost??

Matt