What is the difference between these Device Settings deployment paths?
Starting with macOS, iOS, and iPadOS 26 Addigy supports the deployment of MDM Profiles or Declarations for Device Settings. Devices on Apple OSes prior to OS 26 will continue getting MDM Profiles just as they always have, and if a device is on OS 26 and up you have the option of deploying a Declaration for a given Device Setting (EX: Passcode, SSOe, PSSO, and more).
There is no end user functional difference in the deployment of these newer Declarations vs. an older style MDM Profile. Some differences do exist in the key (individual settings EX: passcode length, or Team ID, etc.) values available from an MDM Profile key value to a Declaration Configuration Object key. Newer Apple OSes 26+ may have new features that are only able to be enterprise managed via the newer Declaration Configuration Object.
How can you tell if my devices in a Addigy Policy will get this Device Setting?
Both MDM Profiles or Declarations in Device Settings will have a required minimum OS listed at the top of the key values if the feature supports only a subset of the OSes that Addigy as a whole supports.
If a device is on an OS that is OLDER than the minimum supported OS the Profile will be skipped and in a Declarations case it will not be activated on the device until it reaches the newer OS post upgrade to or past the supported version.
What if you deploy both a Declarations and an MDM Profile to a device for the same Device Setting?
Per Apple OS guidelines a Declaration should take precedence on the device if that is present over the older MDM Profile. For example if you have an MDM Profile that is managing the OS Updates Deferrals but you also have a Declaration for that feature (applied via OS Updates in Addigy) those newer Declaration values would take precedence on device, the same goes for Passcode profile (Legacy) vs. the Declaration via Device Settings.