Hi @k2director 
I don’t know if that answers specifically your question but there is here a beginning of the answer.
As mentioned in this SO thread, there is an active discussion on this forum you can find here as well as an article worth reading here.
In a nutshell, I guess the idea would be to scope who can view the updates based on the partial you broadcast and passing variables to handle that filtering (as described in the thread, for example, passing current_user as a variable).
(As an alternative also, I think StimulusReflex can be interesting since it can access more “backend” information with helpers like updates_for)
I hope this helps you a bit.