Auxiliary Windows on top

Whenever I am working with the Mixer or the Play pannel, and going back often to the score, it is annoying because every time I touch the score to keep working, the Mixer dissapears behind. Other music software have a "pin" icon that allows this secondary windows to stay afloat when returning to the main interface (if decided by the user), which I find an excellent and productive idea. Picture shows this feature in DAW Reaper. Could this be implemented? Thanks