1

I'd like to have an option for autodelete "favorites after XX days", "other contacts after XX days" and "strangers after XX days", where 99 = no delete.
Can this be done?

2

What users really care about is the space occupied, not how old a file is. So we think the idea "automatically delete old files when total space occupied exceeds a predefined number" is better than the idea "automatically delete files that were older than a predefined number of days".

You can define the "Call Settings - Max Space Limited (MB)" option in Boldbeast Recorder, then it will automatically delete old files if needed.