One of the perils an adventurer has to endure is lag.
Forts and other busy places can slow the game down a lot.
For several reason my adventurers had have to return to these laggy places on a regular basis.
So I created a special minecart track entrance to the fort. The tunnel ended near the edge of the map. It started at the booze stockpile. Which was fairly close to other stockpiles my adventurers frequented.
Next I made a copy of the fortress and retired. Copies are not for save scumming. Copies are required because switching modes and using hacks will not produce a stable game. Game crashed a couple of times. Backups saved to day (most of it).
Next I played as adventurer starting in my own fort. Keep changing peasant/local hero till you spawn at the right place.
With the adventurer I created a site, right next to the fortress. Now it was time to start digging again. With gui/advfort in the dfhack console you enable the possibility to dig with your adventurer. Once it is enabled, use ? for options.
Digging is quite easy. Don't forget to get a pickaxe from the fortress. Track carving will have to be done in both ways, e.g. both from north to south and south to north. Digging an up ramp was a bit harder. Eventually it worked.
Now I had a site next to the fort where I could ride a minecart right into the heart of the fort, fill it with booze, quires, logs or whatever takes too long or is too hard as an adventurer. It was glorious.
In fortress mode, I hardly use the ride minecart option. In adventure mode it is great fun.
As for safety: minecarts do ride on bridges. The minecart tunnel had a bridge to close if needed. I did not play long enough in fortress mode again to see if anyone comes through.
You could try and use wooden minecarts. But better have an adventurer that dodges well or push a minecart while riding again just before ramps. Getting stuck just before a ramp and fiddling around with minecarts that roll back at a ramp are !fun!.
I do not know how far you can extend this craziness. Game crashed again when trying to install a lever in adventurer mode. Going to try and extend machinery across sites. Likely will not work but.. for !science!
Possibly you can link multiple forts this way, using adventurer sites in between. If anyone comes up with some great scheme using this, please post. I'd like to know the extend of what is possible with this.