EverBrook

I've often searched for an idea like this, as I am a fan and user of Workflowy, that is based around this idea.

I'd just like to embed some Workflowy sections in to Evernote and be able to work in Evernote, instead of bouncing in and out of different platforms.

A small example of my own of how it looks... https://workflowy.com/#/f1a99c68ba5b but their own website has more in depth videos to explain. It's so simple, infinitely expandable and quick.

Greatly disappointed with the Beta version. I have Notebooks shared with my wife's Evernote account, and after selecting to switch to the new version, all the Notebooks I share with her do not show up. Can't search for them, even with links I copied from the older version, in the new version they don't show up. When clicking on Share with Me in the new version there was just a welcome screen message of nothing being share yet. Thousands of important notes suddenly not being able to be accessed is very scary for us. Please fix this critical error. I have checked this using Chrome and Safari on an iMac, both displaying same problem. Many other Forum users have noted the same errors.

Maybe "Dave" has a nest of Tags. He could name his nest "Dave" and then all of his Tags go under that.
You then would do the same thing, if sharing your Tags back with him.
Then, maybe, just his Parent Tag shows in your list, and if you needed to see the others you could expand the list?

Haven't tested that though, just a thought.