This does not work for me. The order 'refuel from target fleet: harvester base' is deleted after the message 'cannot complete orders, not enough fuel'.
The tanker does not wait until it's full
It just grabs as much fuel as there is available, and proceeds to drop it off at the designated point.
If I cycle the orders, this will eventually result in the tanker running out of fuel while transporting it, because it keeps dropping off 90% of it's fuel, but not gaining enough at the fuel base to compensate.
I tried some different orders: I set the conditional order: if fuel tanks full, unload 90% fuel at colony within 4 jumps, combined with the cycled order: refuel from target fleet: fuel base, with an order delay of 1 month (to prevent my increments getting cut short all the time from the cannot complete orders message spam).
This worked swell for a turn. Unfortunatly, the game does not remember order delay setting when cycling moves, so after one 1-month increment I was back to getting an interrupt message every 2 hour increment.
Now I just give my tankers the command to refuel from the bases manually every month, combined with the 'fuel tanks full >> unload 90%' conditional order.
For now it's doable, I only have 2 fuel bases and 2 tankers, but I can see this becoming a major PITA when I will have more bases and tankers running, if I have to keep doing this manually.
Really now, how can I set up a set of repeating / conditional orders so that I do not have to look at my fuel bases / tankers manually every month?