Umbrella Memberships

I'm looking for the ability to do umbrella memberships. Where there are user accounts setup under the payment of another account. This could be education consultants signing up a set of students, The subordinate memberships are dependent on the primary membership holder paying the bill. If that one expires, they all expire.

It could be setup where the paying member buys a number of seats, with different levels of seats available at a different price points.

Currently, iThemes Echange membership add-on is the only one out there that supports it. But there version of membership isn't very good, just an addon to their ecommerce plugin. I know that Pippin Williamson has this feature on his road map for Restrict Content Pro, but that may be a while yet.

Umbrella memberships were something that Chris Lema talked about last year when he did his epic review of 20+ membership plugins. He noted that it would be a desired feature in a membership plugin. I currently have two clients right now that have a need for this type of feature. For one of them, I'm having to custom build something using Formidable and user registration, but this is something I'd rather see in a membership plugin.

Do you guys have an opinion on this? Have you looked at it?