It's a fairly simple task to adjust the dynamic range or overall range of a pro piano SMF... Simply compress the velocities a hair, and add a hair of overall velocity to adjust for a sequence that drops down too far, or simply add a little velocity if it doesn't get into the upper range samples and ppp seems too quiet.

Finer detail can be done if needed, but on the whole simply scaling and/or adding/subtracting fixes the problem.

Trouble is, you'll find few to no pro piano sequences performed on an arranger keyboard in the first place. 60 notes simply doesn't cut it unless you are doing Bach or Haydn...