Hi Steve,
Thanks so much for the amazing work you've put into this.
I rushed Sorium Harvesters to see if the bad behaviour was still there, and it is, due to either my fault or a bug.
My Sorium Fuel Harvester fleet (EDIT: of Fuel Harvester class) does the "Home World: Transfer Fuel to Colony" and "GAS_GIANT_WITH_SORIUM_HERE: Move to Location" cycle perfectly, but it doesn't deposit any fuel in Earth (I froze Fuel Production, and after a couple of years of the fleet going back and forth, the amount in earth hasn't changed)