It would appear that if files referenced into a dynamic view master file have pointclouds attached which are turned on, even if they are in a level which is turned off will only print as a tiled raster.
When you are working with a large number of active files that are referring to a number of pointclouds this starts to get very frustrating, because there is a repeated process of going through each file to check pointclouds are turned off to enable printing to work correctly. It stops the printing workflow being automated.
I suppose this is a CR - perhaps at Display Attributes level or at print dialog level it would be really useful to be able to toggle pointclouds off or ignore them to allow vector printing.
I guess another alternative would be for referenced pointclouds to respect nesting depth. This would allow the DV workflow that I believe most people use, which is to reference in with no nesting to have complete control over what ends up in the DV.