If Organization B grants access to Organization A’s Super Admin user, and all members of Organization A are assigned as having Administrator role, will all of the members of Organization A be able to access the Organization B account? Or will the Super Admin be the only one that can access Organization B’s account?
I may have misunderstood the use case. Are you trying to have multiple people use MFA for a single shared super-admin user? I think the easiest way is to save the TOTP code safely somewhere, and have each person add the code to their TOTP app of choice (I like Authy, but they are all essentially the same).
Not really the best idea from a security perspective. Just remember to roll the code every time somebody leaves the team.