Is it possible to set Severity on Activity Log Alert Rules? (Microsoft.Insights/ActivityLogAlerts)

Within Azure Monitor is there any way to set the severity of an Activity Log, Resource Health or Service health focused alert rule? (Essentially all of type Microsoft.insights/ActivityLogAlerts)?

This doesn’t seem to be possible in the portal and there is also no Bicep/ARM template field for Severity I can find. They always seem to come through as Sev4

Both log query alert rules and metric alert rules support setting severity.

Is this really not possible for ActivityLogAlerts?

My use case is that I would like to assign ResourceHealth alerts for critical production systems severities of 0 and 1, while less important systems get 2 or 3 depending on the resource group / specific VM

Am I overlooking something or is this a pretty big gap in functionality?

Many thanks

jens