MUA is enabled by default.
When you use the same email to access dispatch information in more than one Call Steward Client.
If you are presented with an opportunity to 'Select Union' than you are a user with MUA access.

After you login, you can look for the "Change Local' switch to navigate from one local to the next.

While there you can look at calendars, update wishlists, and confirm calls.

This means that the following information is shared between your dispatchers.
Your Recurring unavailability appears in both places

Your Vacation appears in both places

Your calls from the other locals appear to your dispatcher in this fashion.

So what is the impact of this?
One dispatcher may skip over you in one jurisdiction because you are booked in another.
Other booking applies UNCONFIRMED offers as well as confirmed offers.
So respond quickly to all offers of work.

You can't lie to your dispatcher about working in another local because they can clearly see that you are.
Calls happen in advance. So when things get really busy, be prepared to get caught between the needs of 2 locals.
You have the right to work in both places, but not at the same time.

You also have the right to be subject to the dispatch rules of 2 locals.
There may be consequences.

Working on the bounce between 2 or more dispatchers can be a challenge.
Be honest. Be respectful.

We can get to work !