Unless I’m completely missing something, it is not possible to attach an existing Page to an existing Project Template. I find this very limiting and would not like to think the workaround is to create a project, attach the page and then save it as a project template. 
Hoping a fast follow is coming soon!
This would be useful, voted!
Implementation Question:
Would you see this as a single page that is linked to multiple projects where the content is dynamically updated when you update the page? Or would this be a page that is created on each project that uses the template?
My question stems from the issue that arose when they rolled out the Knowledge tab and the “Pages” vs “Notes” transition where you ended up with quite a number of pages that are named the same and have the same content because they started as Notes tab in a project template.
Exactly that - one source of truth!
This is exactly what I would want out of an SOP type library/scenario. Especially if then you could reference those SOPs from AI Studio/Agents.
