Lowering Aileron Effect / Performance at slower speeds?

I mentioned aerobatics because you can use 1538 only effectively at or beyond stall AoA, hence it's IMO not useful during normal ops.
This is an incorrect statement. Cl_r is very much a part of normal flight. 1538 allows you to scale Cl_r based on AoA. A good example of this is any aircraft with dihedral. The effect of dihedral will change based on AoA. In conjunction with 1537, as the AoA and roll increase, the high wing becomes a deflected rudder near the CoL.