Production buildings would prioritise delivery to secondary production buildings within range over delivery to warehouses whenever possible. This leads to serious problem when the distance between the buildings is large enough since there are no enough carts to carry all the products away and reduces the productivity of outgoing buildings due to full storage. The problem can easily arise from orchards having long range, or if I am overproducing certain good that is to be transported to other islands while also using it locally. The following screenshot is an example. The coal mine is delivering to filament factories far away over the warehouse nearby, causing a productivity drop.

An option to prioritise deliveries to warehouses should help a lot.

The AI for trains is stupid. This is especially visible on Crown Falls. I have 4 oil power plants on Crown Falls and it drives me crazy seeing all 7 trains going to the same plant when other 2 are low on oil. I alone can think of better ways to implement train logic, many games (even very old) are better in this regard. It is on the edge of game-breaking. I am aware that gas power plants are available but they are much more limited in availability.
You already have my money but you'll really sink in my mind if you'll be unable to address this issue. The AI for trains surely isn't that integrated into other aspects of the game. Please, repair it.

My oil trains sit idle well past an oil refinery becoming full, halting production and slowing down the chain.

In the picture, both refineries are full and there are 6 of 7 trains idle. I would expect the trains to operate like ships and continuously be on a route, but they'll just sit idle until they are good and ready.

What am I missing? Is there a way to force them out?