This may be too simple an answer to what may be a more complex issue than I am understanding but . . . to increase RT & RD volume I click the "Sax Icon" and/or "Drum Icon" right under the Medolist and Soloist Buttons on the main BIAB screen. Each one will bring you to an option to increase RT Volume or for RDrums you have one more step and that is click the "Settings Button" near the bottom right side of the screen. Both will take you to another option of increasing the volume of RD and/or RT's.

Later,