multiple piano rolls open at once?

Is there a way to do this? 
 
I have a sequence that is played in part on one softsynth and another part in another softsynth, the melody being intertwined.  Editing would be easier if I could keep both PRV windows open.

As an alternative to FBB's excellent suggestion, you can also use the pick tracks function in a single prv and open as many tracks as you want. Use the control key to select non-contiguous tracks