I guess I never noticed. I'm pretty sure I would have increased refinery health pools. Maybe I don't notice it on mine because all the Carryalls are slower so maybe they never fill all three docking pads at once.
I haven't messed with this value but at the top of rules.txt under General, there's a value:
MinCarryTileDist=10 //carryall pickup harv
I wonder if decreasing this would allow harvesters to move on their own more. It feels like the Carryall will pick them up depending on how far they gotta move.