This is pretty simple to do in FFCore. Here's the workflow
The Split component sends all pages that are 11 x 9 to the top branch. It sends all pages that are not 11 x 9 to the bottom branch.
Using not 11 x 9 in the check allows pages of any other size to go to the bottom branch.
Since the tabs are simplex, we can then remove the blank pages from the tab file
Received the following question via email
Can you FF Core to strip out the tabs (all 9x11 pages) from a job and produce two files, one with just tabs and one with the rest of the pages?