Remote User Sync question for the developers

Newbie with the plug-in, but loving it, but help welcome as I think out loud on this.

I’ve got 11 sites with a nonprofit, eight sub domains and a dot org and dot com.

Would it be wise to create another subdomain, LOGIN.domain, for the purpose to sync user login status and account creation with one site?

Presently:
https://SwimISCA.org
https://hub.SwimISCA.org
https://blog.SwimISCA.org
https://read.SwimISCA.org
https://code.SwimISCA.org
https://pool.SwimISCA.org
https://time.SwimISCA.org
https://help.SwimISCA.org
https://map.SwimISCA.org
https://app.SwimISCA.org
https://SwimISCA.com

Could create:
https://LOGIN.SwimISCA.org

Typical hub and wheel design, of course.

In quick tests last week, I had 4 sites all connect to the Blog.SwimISCA.org, but that put an extra 20-40 seconds delay into the login with the blog. It had to connect to all those other sites, of course.

I’d love to see the user visit one of the sites, login, of course, then have that sync go to only ONE site. Faster. Then the user experience is not dragging. Then those other sites can communicate to each other while the visitor surfs the pages at the first site.

Make sense?

Is that how WP Remote User Sync works?