If you don't need interactive/animated features, I can absolutely recommend to have the agent build slides in HTML and convert it to PDF. Has been a game changer for me.
I’m having trouble having it take reference PowerPoint slides and converting them to html, chart and labels misplaced, the charts don’t look drawn properly, etc. how did you solve this?
I don't have a great solution here. I rebuilt our PPT master fully in HTML and I'm using a modified version of Google's DESIGN.md to store the references.