"the loader could have an screen showing stats for updates and note if ones missing."
There's a lot of fluff going around, portable devices are labor intensive no matter how they are updated.
There's only one way to get the labor out, and that depends on the FAA type authorities, aircraft manufacturers.....etc. There's liability in plugging portable devices directly into aircraft infrastructure power sources, with regard to battery replenishing or any other reason and leaving them on aircraft. Having to remove them for that reason on-board updating is mute, be it wireless or any other manner.
e.Digital needs to take it to the next level, perhaps they can do just that now that their hands are untied.
doni