The authentication endpoints for AAD in US Gov (FF) changed a while back - I believe that for all 3 methods coded here, the endpoint is login.microsoftonline.us instead of {'login.windows.net','login.microsoftonline.com','secure.aadcdn.microsoftonline-p.com'} - around line 1500 of AzureSQLConnectivityChecker.ps1 - I'm not sure about for BF and MC. So while this does support gateway and cluster for a us gov database, I'm not sure the endpoint tests are appropriate.
The authentication endpoints for AAD in US Gov (FF) changed a while back - I believe that for all 3 methods coded here, the endpoint is login.microsoftonline.us instead of {'login.windows.net','login.microsoftonline.com','secure.aadcdn.microsoftonline-p.com'} - around line 1500 of AzureSQLConnectivityChecker.ps1 - I'm not sure about for BF and MC. So while this does support gateway and cluster for a us gov database, I'm not sure the endpoint tests are appropriate.