Nick,
I'm sure that you've been heads-down on the Starship for a good while now, but I was reminded of this issue yesterday when I pulled into the ramp at Nashville yesterday. I selected external power and went to play with the avionics after I shut everything down, and found myself eating through the battery instead of being connected to the power cart. Fortunately, it gave me an opportunity to play around with hot starts and vapor lock (and watch it all on the tablet as I went through the hot start checklist!), and I could always just click "recharge battery," but having the power cart would still be nice.
Have you had a chance to look at this for the next round of aircraft updates?