Printing on a KM 7000 with an external Fiery on CWS5

Printing pads and unfortunately with the KM RIP there isn't pad printing available so ...

It is an A3 document 52pg PDF and inserting a slip sheet after the last page. It is taking a long time to RIP. The printer actually catches up with the RIP processing the file so gets to about pg20 and then processes a bit more and then prints a page or two etc.

I have the Cache PDF and PS objects on with Record length to 1 (because all the pages are the same)

Is there anything else I could be doing to speed it up at all?

It also put the slip sheet in after pg17, not the last page!? Not sure why and not very helpful!