Is there a trick for Anno 1404 to automate transportation with min/max?

Anno 1404 has two modes of trading / transportation:

1. Trade routes. This is both for trading with NPCs, and for transportation between one's own settlements.
2. Passive trade settings for NPCs that visit with their ships. This setting is equivalent to min/max values (I think), but it is limited to trading with others.

Unfortunately, the option 1 (trade routes) needs continuous babysitting:

• Ships always pick up as much as they can, and don't care to leave a minimum stock.
• Ships always take the first item in the queue, even if other items have a higher stock. E.g. they rather take 2 pieces of wood than some of the 150 pieces of coal, if the wood is first in the queue.
• Leftover goods stay forever in the ship, which means the ship may go back and forth without trading anything.

The only in-game solution seems to be to frequently change the trade route settings.

It is killing the fun of the game for me, so I thought maybe I am missing something here.

Related questions:

• In Anno 1404, is there any way to automate swapping resources between settlements?
  This is just asking for trade routes.
• How do I maintain a constant amount of a good on an island via trade routes?
  This is for Anno 2070.