Thank you for considering Aspose.
I am afraid, the requested feature is not supported yet in Aspose.Slides for Reporting Services. A new feature request has been registered in our issue tracking system with issue id: SLIDESREP-33412. Our development team will further look into it and check the feasibility of supporting this feature. You will be notified via this forum thread once there is any update regarding this feature.
Thanks & Regards,