We are working on this right now with Entity-level permissions, although it’ll take a while.
As a part of our current plan, we’ll introduce a new kind of Users in addition to Admins, Members, and Guests — specifically to accommodate external collaborators. Inviting an outsider to work on a doc or a task should become frictionless. Notion and Google Docs do this well, we’ll take a page out of their book and put some Fibery sauce on it (not sure if the result will be edible 
).
Retrospectively, labelling the current read-only users “Guests” has led to some confusion. However, the proper Guests are coming 