Per the following articles, you should be able to assign each of the TIDAL member accounts to a unique Plex user account:
https://support.plex.tv/articles/an-intro-to-tidal-with-plex/
https://support.plex.tv/articles/adding-tidal-subscriptions-to-plex/
You cannot have multiple TIDAL streams on a single Plex account (as this equates to multiple streams on a single TIDAL member, which isn’t allowed), but you can link a unique Plex account for each TIDAL member in the family plan.
Note that you cannot purchase a family plan through Plex. If you want to go the TIDAL family plan route, you have to purchase the plan directly from TIDAL.
