Thanks for your inquiry. I am afraid the requested feature is not supported in Aspose.Pdf for SharePoint. However we have logged an enhancement ticket PDFSHP-33407 in our issue tracking system. We will notify you as soon as it is resolved.
Adding more to Tilal’s comments, Aspose.Pdf for SharePoint is currently not support with SharePoint 2013 but we already have logged an investigation ticket as PDFSHP-33223 in our issue tracking system. We will further look into this requirement and will keep you posted with our findings.