I’m in Australia, so my perspective may be skewed. The trailer would be optional, and I only mentioned it as the system as proposed could be just an extension of the self contained removable battery in a vehicle.
Unless batteries can become tremendously lighter, I see a standardised, swappable EV battery a given as a means to further increase vehicle efficiency. Why lug around hundreds of km of range when the distance between typical charging points is a fraction of that.
Maybe this already exists, but what about a feature which allows tagging a post as a link to a previous/original post, which can be used by clients to filter out reposts if desired.