Well I've got it set.
Primary order is to move to gas giant with sorium
Conditionals are if fuel tanks are full, unload fuel at colony.
If I SM fuel into the ship, it'll fly to Io, drop its fuel, and then head back to jupiter, where it sits, and its fuel holds never fill. So I'm confused.
If I add "if fuel less than 10%, refuel at nearest tanker" each 5 day increment, it picks a harvester to drain, and trips the conditional orders, grinding gameplay to a halt, because the tanker is quite large in comparison to the harvesters. I don't mind it sitting there filling up for a year or so. But I don't like being locked into having to restart the game every minute due to the conditional order interfering with autoturns.
Edit, oh yeah, also with this setup, it'll never fully fill. it stops after 10% filled, and never goes up past that point