Train Fuel depart condition

Dedicated train fuel station should be able to hold a train till it is full. Currently train will leave if the filling station runs out. Ideally you should be able to set it if it can leave at like say 25,50,75, or 100%.

Just do not let it run out - you can add additional fuel storage as a buffer. Also you can add fuel platforms to all in-base stations so your trains do not need to go to dedicated fuel stations making them more effective and putting less stress at sudden fuel demand.