Backward motion, 0.
Once you get over that fault on a boat with a prop in an aperture, you can relax.
My boat will rotate counterclockwise - forever - by backing and filling.
You can exaggerate this effect while going forward, by turning hard to port then applying reverse. The boat will skid, slowly, to a stop turning counter clockwise.
The last of the boats forward motion converts to pure sideways - to starboard - for a few more feet. In fact, with the right speed and backing-filling, this is your only move to 'back up' , a short distance, into a slip (challenging...).
Naturally, we utilize this one trick in docking - starboard side to (the lifeline gate is located starboard side, not be coincidence).
When wind and or currents require something different than the above, it becomes a real puzzle that we often solve by not docking. We're not afraid to use lines or handing the boat, off or on a dock.
The upside to a prop in an aperture with a long keel is you can sail the coast of Maine with little regard to lobster pot warp.
I happily take this quality over the above negative. There isn't much dockage on our coast, anyway.