Might add a "learn to build a charger" persistent somewhere, and from that, with tools and parts, be able to repair one wherever broken, and build one wherever there is electricity. Or maybe.. there are so many steps that build up electrician know-how, as well, maybe with enough of the electrician skills the idea that you can repair, and later build, a charger pops up?
Maybe building or repairing a charger will help with the VTOL later? Could be a fun piece of content - unless you've added and charged every single piece of battery into it you'll have to make a pit stop and repair a charger. But, on the other hand, the activity where that would make the most sense is probably already done and this would add lots of work for you. I don't know, you know where you're at and I'm just popping ideas that you've likely heard already.
Excited for the next update! Considering your update history I'm guessing it'll be in a month or two? I'm at the VTOL, raring to go!