Right now one gets stuck when using the adjust key and one cannot lean when in high/crouch or in high/standing or in high/prone or in the low equivalents. If you guys have played Medal of Honor: Warfighter (Which I imagine is the case because of this new key feature) your character snaps back into the previous position after you release the key (alt by default in that game, ctrl in A3a).
I would suggest making the key smoother like in MOHW with the option to either snap back into place or a toggle option. This would allow a player to lean when approaching a door, release the key if they are shot at to snap back into cover, or alternatively release the key as they enter the room so that they may move faster.
This would make the game feel 10x smoother, in my opinion, as well as allow the user to unbind the keys for specific leaning commands. Imagine, popping up and firing a couple rounds then dropping back down when you release the key.