Having the option to decide what presence sources needs to be considered in aggregated presence state is a nice feature to have.
Yet we have a customer asking for the option to be able to combine the use of presence sources with an IF statement.
Another solution to this could be to add priorities to aggregated presence sources.
Example:
The "calendar presence" only activates as an aggregated source IF Teams presence OR mobile presence IS unavailable / grey.
Teams and mobile= High priority
Calendar = low priority
Benefits:
This option would make it possible to avoid errors when a user dials another user whom is grey in Teams and mobile presence, but is available / unavailable in calendar.