I have just downloaded new version of RexPaint, because I needed more layers ^_^.
May I suggest a change to how you should handle extended layers?
Instead of pressing E to show 9 layers, add <> and always show 4 layers. In case of 6 layers:
Pressing > will move indicator upwards and you will see on first press 2,3,4,5th layer, pressing it again: 3,4,5,6th,
Pressing < will move indicator downward 2,3,4,5 then 1,2,3,4.
In this case you will always have info pane visible, and if you like it, you can even increase number of layers over 9.