It appears the newest version of Scratch doesn't support extensions via the mit web site. However, looking at the source for the Scratch 3 GUI at:
https://github.com/LLK/scratch-gui
I see there is an examples / extension folder. I think it would be worth hosting Scratch on Dexter, with the extensions pre-installed to work with it. Is that a project that interests you?
It appears the newest version of Scratch doesn't support extensions via the mit web site. However, looking at the source for the Scratch 3 GUI at:
https://github.com/LLK/scratch-gui
I see there is an examples / extension folder. I think it would be worth hosting Scratch on Dexter, with the extensions pre-installed to work with it. Is that a project that interests you?