I went back to my hauling routes and stops, after my early excursion into moving carts. Each stop gets a list of stockpile parameters, and the stops can be linked to stockpiles and given conditions before the vehicle is set to depart. So you could get a dwarf to send the minecart along when it becomes full or when it is at least halfway full after two weeks. I'm still finishing that off, mainly the sending along part. Depending on the track, sometimes a dwarf can just kick the cart, sometimes it'll have to be pushed all the way, and with the powered tracks and carts taking flight and triggers, the choice will probably be left up to the player rather than having the computer trying to decide.
You can have the camera follow a unit or item, either as a one time thing or as one of the function hotkeys you set up for it. It'll keep following it until you enter another mode, recenter to an announcement, manually scroll, etc. If the followed item is held by a container or by a unit, the camera will center on that.
TL;DR - You can tie a cart station to a stockpile and set up the "launch when" conditions, such as "launch the cart when it's full" or "launch it if it's been sitting here for too long". Depending on the track setup, the dwarf will either send it along, or may have to push it the whole way, this being mainly defined by how the player builds their infrastructure.
You can also set hotkeys to follow specific items or creatures. Just like DFHack has the "follow" command, vanilla will now let you camera-chase your axelord into battle.
What I take from this:
##U
>>>>>#===#
#===#
##
+##
connected to:
########
>>>>>^########
This is a basic setup for an automated smasher, of sorts. The red door is linked to the red pressure plate. When the
mayor goblin steps on the plate, then it opens the door. When the door is open, it triggers the stockpile for "begin filling this cart with lead bars". The cart is set to "launch when full". Thus, dwarves will quickly pack the cart with heavy items and launch it, where it careens down some complicate path and hits a goblin upside the head. The door will then lock again, and the trap gets reset.
Possibly more importantly though: You could set up routes to the trade depot which would deliver finished goods to the depot, and have the condition "if these carts are less than full, send them" so that they will immediately head back to the workshops to be refilled with crafts. You can very effectively keep your depot with items one tile away and minimal hauling!