BusyOnBusy default setting when user controlled - Graph or PowerShell available?

Hi,

currently we are checking updating our global calling policy to set the busy on busy setting to "user controlled". Our current setting is "disabled". After some testing we found out, that changing the policy from "disabled" to "user controlled", the individual user setting will be "let the call ring" instead of "busy". Is it possible to define an default initial value for all users or is it possible to set this setting on a specific value for all users (e. g. via powershell, graph, or similar)? I could not find anything about this in the documentation or roadmap.

Best regards

Marc