Save As PDF, DocumentVisible False

I've got a Macro at the moment, that trawls an assembly for all the dependancies for the file. (Using Get Document Dependcies2)

From here I want to export all the drawings as a PDF which is all fine, It opens each one up in turn and exports it. however as some of the drawings have very big assemblies behind them, it takes a long time to render them out on screen and refresh them before saving. I have a similar trawler that goes though and generates STEP files as well, however this I managed to dramatically decrease the time to run by using:

swApp.DocumentVisible False, swDocumentTypes_e.swDocPART

When I use the same above command but modified for drawings, it doesn't seem to save. It does however override anything that is saved in that location with nothing, it just deletes the file. Is there a way to speed up the execution of this another way to stop it rendering, and thus cutting the time down. Or am I a little stuffed?

VBA, No access to PDM.

SolidworksApi/macros