When creating custom properties in my presentation and saving as a PPTX file, I can see the properties in the PowerPoint inspector just fine. But when I save as PDF, they don’t appear in the Acrobat Reader properties inspector. I suspect this is a bug, or possibly a feature omission.
Thanks for inquiring Aspose.Slides.
I have observed the requirements shared by you and request you to please share the sample code along with source presentation and generated output PDF file with us. We will investigate the requested information and will then be able to share further feedback with you in this regard.