Hi all 
As a follow-up to the original video, I’ve now created a new video showing how to achieve the same plugin workflow using the Rhino Script Editor:
Rhino Script Editor-based Plugin with DKUI
This method has its own unique setup requirements, but offers a potentially smoother user experience—especially since it allows the script to close cleanly on demand.
Additionally, as an appendix to that video, I’ve included a short tutorial on how to add and manage custom icons and start buttons within the plugin:
Adding Icons and Start Buttons to Your Rhino Plugin
Hope this helps anyone looking to polish their UI and plugin packaging workflow!
Happy to answer any questions or clarify anything.