The problem why the alternate pdftops does not work is that it produces non-DSC-conforming PostScript but advertizes it as DSC-conforming. This leads the CUPS pstops filter to fail, the filter which handles the double-sided attribute and which also crashed on the long document.
I have fixed this in Ghostscript upstream (SVN rev 9748) and also made a workaround in the alternative pdftops filter for the time being. The new version of the filter is attached. Please test.
The problem why the alternate pdftops does not work is that it produces non-DSC-conforming PostScript but advertizes it as DSC-conforming. This leads the CUPS pstops filter to fail, the filter which handles the double-sided attribute and which also crashed on the long document.
I have fixed this in Ghostscript upstream (SVN rev 9748) and also made a workaround in the alternative pdftops filter for the time being. The new version of the filter is attached. Please test.