A Mela user made me aware of the use case where he wants to make adjustments during performance by grabbing the main XY handle. However, due to the fast nature of his performance, he often misses it as the target touch area is not large enough for this type of use.

The solution is to make the whole background touchable. i.e. dragging the finger anywhere will move the XY handle. This means removing the independent X and Y handles (small circles). But this is OK because the user can still control parameters associated with X and Y independently via the dials above the XY Control.