Individual profile schema: No, normally you would not need to collect the ECID as a record as a person could have multiple ECID over time. Experience Event schema: No, When you enable Profile for an event schema without a primary identity, then the system will remind you to send the identities such ...

Signals that were already sent to AAM cannot be deleted. However, you can prevent Analytics data collection hits to be forwarded to AAM (and hence excluded from usage) by using the contextData attribute: s.contextData['cm.ssf']='1' More info on how to implement here: https://experienceleaguecommunit...

Make sure to enable “Migrate ECID from VisitorAPI to Alloy to prevent visitor cliffing” as part of your Web SDK (alloy.js) configuration. This will check the AMCV cookies from ECID service before requesting new ECIDs. That being said, please do you own testing.  

No matter what data layer is used, the source of the data should be from the website (application layer). If you are referring to the Adobe Client Data Layer, the extension can load the library however, the website will still need to populate the values in it.

Segments created in the UI and API cannot be edited other than the original source. Facilitate management of Segments, bulk creation and allow adjustments in the UI. 

Exporting array fields is not supported at this time.

The  "All Cross Device" profile merge is most appropriate for People Based Destinations rather than DSPs  (which are device based). Normally, it is recommended to use Last Auth + Device Graph to maximise DSP reach and instant cross-device qualification at the DSP end.

Try to use ... matchesregex "^$"and let us know how you go.

In iOS it is called IDFA and for Android it is known as the GAID.For iOS, set the Device ID using the method 'setAdvertisingIdentifier': Configuration Methods Example to retrieve IDFA: ios - How to retrieve iPhone IDFA from API? - Stack OverflowNote that this is a general response. I would reach out...