A connection to Squared Up counts towards the 50 simultaneous user SDK limit. However a Squared Up SDK connection generally puts lower load on the SCOM infrastructure and in our testing we scale well beyond 50 concurrent connections.
If your users only need access to static non-interactive dashboards, we recommend using Open Access dashboards where users can access up to date images of dashboards. See About Open Access
The following PowerShell will list all the users that currently have a SCOM console connection. Users will be displayed once for every connection they have open.