I have a list of top level pages which use a variety of templates.
I want editors to be able to create a new page, but be limited to one template.
Can I do this from the editor.yml file?
No.
You can set the create: option in a pages section.
This setting cannot be set based on user role in a yml blueprint though. If you want to make this dynamic based on user role, then you can take the programmatic approach to blueprints:
Thank you, working nicely now.