Book Module: How to export two page spread in PDF to show as SINGLE image?

Hi,

1.  I'm relatively new to the book module in Lightroom;  I've been using Apple Photos but in that they're no longer supporting books (directly), I've been forced to use Lightroom.

2.  I'm able to create a basic book and often use the two page spread layout for my panoramic images.  

3.  Question - Issue:   With Apple Photos, once I'm done with the book, IF I want to save as a PDF, I simply "Print" and then save as PDF;  the book is perfectly converted to PDF and their two page spreads are saved as a true long/ panoramic single image (I would do this by creating a custom print size in the print dialog box).   With Lightroom CC, there doesn't seem to be any way to export the PDF so that the two page spread shows up as one image; rather it's broken up into two separate pages, which I understand if one wants to create a book.    I've done some research and modifying Acrobat Pro to show something like "two images up" isn't an option for me because then the whole book shows two pages at a time and even the two page spread is still separated by a seam.  

     Does anyone have a simple solution for this?   It would be great if Lightroom simply offered the ability to modify the "print" parameters when creating the PDF.  

4.  The only solution I've discovered by experimentation is to create the book to JPEG (which does create a single image two page spread), then convert all of those JPEGs to PDF and then combine in Acrobat Pro.   Adds some extra work, but I do end up with what I want.  

Thanks in advance for any help,  Harry