Great resources to learn about PDF++ by the community.
YouTube videos
PDF++: The Best PDF Plugin For Obsidian by Prakash Joshi Pax
See also my notice in the comment section.
Excalidraw Obsidian 2.4.0 Feature Walkthrough by Zsolt Viczian
Zsolt, the author of the Obsidian Excalidraw plugin, demonstrates the PDF++ integration feature he has implemented in Excalidraw v2.4.0.