How to understand why Different versions of PDF’s are generated by DOC1

Product Feature: DOC1GEN

A1: The Fonts used in the Application could be mixture of DBCS (PDF-1.5) and Open Type (PDF-1.6) resulting in the correct PDF-1.6 version at the top of the file

A2:  For a “consistent” PDF Level of 1.5 , replace the use of “Open Type” Fonts (PDF -1.6) with True Type.

A3: No, The PDF Level at the Top of the file MUST reflect the Highest level PDF Object used in the file in order to comply with the PDF Standard.

Currently there is no way to specifically set the level of PDF output by Generate. This is determined by the content of the publication, so if you require this to be a specific level, you will need to use a third party tool to create this.”

Please note that no PDF Producer can produce VALID PDF using Open Type Fonts at a lower level than “PDF-1.6” as per the PDF 1.6 specification which introduces support for Embedding Open Type Fonts
UPDATED:  August 25, 2017