PVA is just more expensive as a raw material, it has a short (only a year) shelve life, and you need to store it properly (dry and not too hot).
@Daid_Braam yes thats the problem. Thats why I asked 
Does not take away that with the proper hardware, proper software, and proper PVA, you can make the impossible 
Sorry but See it as advised. … that are old open source product now only in “kit” … exist Fum /flusso canalizzarore(4way) / cylops / diamond and other version in thingverse ect… made it diy, if need, we have a 3d printer