Not sure what the question is but if you want the outline info saved you need to use the PXF. PXF can be 'sent' to the machine (it just converts and sends it over the LAN connection). If you scan from a folder though you need the .DST and you need your PXF still to hold all info.
I would keep both files and label appropriately so you know if versions change. These files are so small to work with it's not a space issue at all.