telephono

Yes, at the moment it looks like the nosegear is only steerable with hydraulic pressure in A. I don't really know, how BetterPushback implements steering but the aircraft somehow has to detect BetterPushback connecting and make the nose gear steerable without hydraulic pressure in the A system. In other add-on aircraft, you even get the appropiate warning lights when the nose gear steering gets disconnected by BetterPushback "inserting" the nosegear steering bypass pin. So it should be doable, somehow...

You can make BetterPushback behave itself if you enable the Left Electric Hydraulic Pumps before starting the pushback. As long as there is enough hydraulic pressure in the left system, the aircraft behaves as expected while using BetterPushback...