MIM SSPR Reset from pre-registered user in sync connected untrusted domain! say what!!

Hello Folks Just as a reminder from a blog post I posted last year   Scenario: In Contoso they have a MIM SSPR deployed currently Contoso Users and register and reset using MIM. They have recently partnered with FabriKam and wanted to offer SSPR for there users without the need for a trust. FabriKam want…