Here's just a small idea for a mod that settlement people might like:

Couriers:

You pay a person to carry as much inventory as a Brahmin can carry (500 lbs maybe?) to settlements in your supply line.

I outfit my minutemen guards with minutemen outfit, a set of combat armor, and a laser musket, laser rifle or combat rifle, and a hat according to their "rank"

Rookies: Ushanka hat, Combat rifle

Veterans: Militia hat, Laser rifle or musket

CO's (One per settlement): Military hat (Beret), Laser musket

All this gear is heavy and frankly delivering it to the settlements is not really a job for a general, so I think it would be a great a idea to be able to have couriers deliver it. They could charge you depending on the total weight of the delivery. You could talk to them, select "barter" and start dumping gear in their inventory. The price for the delivery would show up just like any other vendor, except you wouldn't be able to lower the charge by giving the courier items. Just straight caps.

This would be different from provisioners because you could send them anywhere, not just within the provisioner route. (provisioners can't be made to carry specific stuff anyways) Distance could influence the price of the delivery too. The couriers could then deposit the gear in a container assigned to it (mailboxes from FONV basically)

Another option would be to assign them to the mailboxes so that you would actually have to build a mailbox out of the workshop before that settlement was included in the list of places that you can ship stuff to.

That's all.

Thanks for reading.