On a single monitor setup, tools such as BE are naturally positioned beside an edit window, usually to the right (left-to-right writing convention > left-to-right window organization [of course there are alternatives]).
Positioned on the right edge, a reference window’s drawer pops out off-screen. If, as per other drawer-based interfaces, the user might specify a left-side pop out, the drawer could be visible without manually moving the reference window over to the left in order to see the extended but invisible drawer.
Would others find this option useful? Disagreeable?