I'm running into the issue of the fop servlet being called twice
This is a known problem with IEx. Use an URL ending in .pdf for the PDF. (is there a law or something that people are generally unimaginative for the URL-to-Object mapping of their servlets?)
and I am getting the following error:
ERROR [fop]:Page subsequences exhausted. Using previous subsequence.
This has nothing to do with the first problem. You have an incomplete page master, check it.