I am on 47.04 and would like to get DFHack as it sounds like it has some wonderful quality of life features, but I figured I'd wait until a more stable release of it that supports 47.04.
The pressure plate does show it has a 2nd mechanism installed, and won't let me link to the door (doesn't show in list anymore when I try to link to door), so I assume it is hooked up correctly.
I was worried maybe the weight triggering settings weren't correct; does anyone know if the pathing algorithm would analyze whether the door blocking the track would go away if they go over the pressure plate? Or if I didn't link it up correctly/had no pressure plate, would a dwarf just guide the cart until blocked by the door, and then sit there waiting for the door to open forever?
I'm guessing the latter; i.e., this isn't an issue with the pressure plate, the symptom of that would be the dwarf would guide the cart south past the plate and just get stuck when the door doesn't open. instead they get the exclamation point/confusion symbol or whatever, and then haul the cart around the long way.
The route is setup almost identically to the working route; head south from the first stop when full of desired items, take from a nearby wood stockpile (this is a difference; the first route takes from the stockpile visible in the screenshot, the 2nd route takes from a different stockpile that is up a few z-levels from the screenshot; this appears to work as dwarves load the cart just fine from that stockpile), head to stop 2 (track stop with max friction & dump to the south, stop orders are to head north when empty of desired items, give to the quantum stockpile just south of the track stop; this is the other difference, the first route dumps to a different stockpile).
Dwarf hauls the cart around outside and through main entrance, plops it down at stop 2 (whereupon it instantly dumps the load of wood that was inside into the correct stockpile just to the south), dwarf guides the cart back to stop 1, they load the cart, and then haul it around the long way again...
One experiment I will try to verify that the door isn't the issue is to delay the cart from leaving stop 1 (e.g., add a timer condition), open the door with another lever (door is hooked to pressure plates on each side and to a manual release lever), and see if they will use the route once the door is open. This will not work properly, I'm guessing (when they trigger the plate it will close the door instead of opening it), but I'll see what happens.
I also made sure to use the same weight cart (copper minecart) in both routes, as I configured the 2nd route's pressure plate triggers based on the weight of the first route's cart, but then saw that the zinc cart I built was lighter and wouldn't trigger them properly. (It had been set up with the zinc cart and the zinc cart had started being loaded, but I swapped it out for copper before they fully loaded it.)
Both routes show the yellow exclamation point with warning "! Set dir/connect track" at both stops, presumably due to the door in the middle of the routes.