MFR machines that store sludge as a byproduct void it when they're full. I guess the same could happen with the autospawner...
Which begs the question, where do items, fluid, and energy go if they're sent through a tesseract that doesn't have a destination, anyway? :/
As for fluiducts, they do "store" fluids; a little bit in each segment. Sort of like saturating the network to provide full fluid anywhere, anytime.
I should add, creating loops is probably not a good idea, because the fluiducts, like energy conduits, are a little derpy when they feed the object they came from...
I've found this out before when experimenting with redstone energy conduits and dynamos: they don't like loops.
Also, I am not sure that the fluiducts coming from the grinders need to be activated. They *may* function just fine when left at the default configuration...