I agree. Used Eastern Beaver box on my B and on another bike before. I attached it to the bottom of the cover on the right side - opposite the little storage box - and used 3M double sided tape to keep it in place. I put it there for 2 reasons: 1) most of my add-in requiring power (phone charger, Garmin & heated clothing plug so far) are all up front, and 2) it is much easier to get to than removing the seat. It has worked great.
Pete