How to get Managed Accounts access to a separate organization's instance as a Guest?

[Matt Briede]

Hello!

Tagged this as Confluence, but there are a variety of apps in play.

I have a client that has a customer support portal through JSM Cloud and a Confluence space that they want to give access to their customers to as Guests. To do so, they converted all their customer accounts to Atlassian accounts so that they could authenticate into Confluence as Guests, as well as JSM. 

The problem is that a subset of their customer base have Managed Accounts with their own organization. When they try to log into the Guest Confluence Space, they are redirected to the SSO process of their home organization, and since they don't have access to any of their home org's Atlassian apps, they hit an error stating they don't have access.

I know that the above is intended functionality; but is there any workaround? It seems strange to me that a managed account of one Org can't be used to log into another Org's instance basically.