Provide portal visibility that is 'creator + internal users' Merged

I observe that Aha has a variety of portal visibility options for its ideas, but a use case we find crucially important is not possible today.

We were recently surprised to see that there is no way to make an idea visible to the creator and a defined set of internal users (say acme.com,*.acme.com) if the creator is an external user, with out making the idea visible to all.

In our enterprise we have many situations where we'd like the idea to be visible to creator and our employees without opening up to the world - some customers might not want to disclose ideas they have for competitive reasons, similarly we have certain products that want to solicit ideas without disclosing publicly.
We really don't want to have to add all internal parties to be aha users as the current Aha behaviour would demand and see additional value in our employees being able to see the an ideas in the same perspective a customer would.

I note that this idea has elements of other ideas - namely:
https://big.ideas.aha.io/ideas/A-I-10042 and https://big.ideas.aha.io/ideas/APP-I-5320 which in various parts of their commentary are asking for what I believe is the same thing. In both cases those ideas have been marked as shipped, which is why I've created a fresh idea.