Add the ability to select specific users in addition to the plans for specific content

I have a use case where I need to restrict content based on plans, but I have, for different individual pieces of content, some additional set of users (low number) that I need to provide access too. Doing this via plans is not viable given the constraints and lack of overlap between them.

The idea here would be to introduce and additional way to "select individual users to provide access to a piece of content (post, etc". It would enable for content to be available to users in the selected plans, AND any individual user manually added to the content.

Imagining something like this: