Dashboard Server and the SDK user limit
A connection to Dashboard Server counts towards the 50 simultaneous user SDK limit. However a Dashboard Server 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 see a version of the dashboard with simplified interactivity we recommend using Open Access dashboards. See Sharing Dashboards with anyone - 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.