Thanks for posts. In our latest version of Foxit Reader and Foxit PhantomPDF 8.1,if need to autoname the generated PDF file and increment with a Arabic numeral if there is
another one PDF file with the same filename already exists,you just need to do the following settings in Foxit PDF Printer properties dialog box:
When you print document with "Foxit PDF printer",click on "Properties"button there to open Foxit PDF printer properties dialog box,please choose a target Folder for saving created PDF files
and choose "Add a numeric suffix"item for the 'If File Exists'option there>click on"Save as default">click"OK"(Please refer to attached screenshot:setting.jpg).
Concerning your suggestion"add the current date and time as suffix in created PDF file name",it has already been submitted to our internal feature system for our product marketing's
reference with suggestion ID#PHANTOM-7293,so that it may be considered in future versions.