Yes in a perfect world we'd have a machine between the cotton and patatoes one which would let the whole plant (flax) on the ground for few days before baling and drying/"brushing" to obtain the perfect fibers . but we're in a Giants game so very far away from reality ^^ and I don't think they bale hemp (not after having this sort of windrow ). So having the opportunity to have the mower in the front and the wagon to the rear to harvest in one passage is not so crazy.
The spinnery accept what WE want :D I know, vanilla spinery accept only bales and pallets but that's not so hard to add a trigger for bulk if you want (ok now you can't on mac OS). actually I added hemp and lin on a map I like where my spinnery produces twine/fabric with flax and rope/fabric with hemp, I just create a trigger and add in the xml
<unloadTrigger exactFillRootNode="exactFillRootNode" fillTypes="FLAX_WINDROW HEMP_SWATH " aiNode="unloadTriggerAINode"/>
so foragewagon can be used if we need.
As said if you want i have a look at the productions to see if that need balance I need to know if we stay with the values I gave in the file or not.