You can find here my test with a water-soluble PVA Wire the SCAFFOLD and POLY PLUS PLA in dual material mode.
After many tests and help with the community, i found this parameters to print the SCAFFOLD with 0.3mm nozzle and the cura 2.7 in 0.2mm per layer. I 'm using a special head "Dual_Balance" but you can also use this paramters with you dual printer with 0.3mm of nozzle. You can find below the picture with all the cura 2.7 parameters for the SCAFFOLD.
You can find below the picture with all the cura 2.7 parameters for the white POLY PLUS PLA.
You can find the 3d model with this link:
The only problem that has occurred is a layer that is detached from the tower caused by my setting on CURA to clean the nozzles. so to avoid!