Ability to move portal users between portals

When you have multiple portals, it happens that a user is created in the wrong associated portal. To avoid notifications from being linked to the wrong portal, it'd be helpful to be able to migrate users from a specific portal to another and ensure the user is seeing the content that matters to them.

The use case is that if a customer and our project managers (or business analysts or support or... you get the picture) are talking, and the staff member wishes to enter the idea in real-time, it gets submitted with their name. We then want to reassign the ticket's creation to the correct user (the customer) who may or may not have logged into the portal at that time. If they haven't, we go ahead and create an account for them so that we can accurately track the submission and go back to them for any questions our development teams may have. Since our ideas can appear in multiple portals at once, the user gets created in the first portal the system comes across (which not might be the right one).

It seems the best practice is not to create the user from the ticket itself (which allows you to do so by just entering their email in the "Created By" field), but rather to create a portal user account in the ideas portal screen then going back to the idea and assigning them as the creator. That seems like a bunch of extra clicks, but would result in the user being created in the right place and assigned to the right portal.