I'd like to be able to hand out access to a primary, single moo.do outline but with selective access focused on one or more "hierarchies" in the larger outline.

I'd like to use this for delegation and sharing. If I tag or flag an outline element as "viewable" by a known recipient, then I'd like to be able to share this access so that others can see and modify anything under that. But where changes are reflected in my primary outline.

In order to support this (at least how I think of it), there could be a lightweight encryption layer that encrypts hierarchies selectively with an ephemeral key, and an initial header is included that encrypts for each recipient the key that is used for this hierarchy.

Then the raw moo.do data could be synchronised directly with the selected other moo.do users even if their Google account is different. And I wouldn't mind handing out the raw information, since I'd assume that the data I'd like to keep confidential can be additionally encrypted.

To keep my life simple and to ensure instant sync, I'd like to hand out access to the one single list, rather than having to manually maintain several lists.