Overwriting ECID in Mobile App

[Joseph_Making]

An older post suggests it is impossible to overwrite the ECID itself in the mobile app. 
https://experienceleaguecommunities.adobe.com/t5/adobe-analytics-questions/override-mcid-over-cookie...

Is this still true? 

We have campaigns linking to AEM pages that deeplink into the native app. Because they switch from browser AEM to native app there is a different ECID and we loose the ability to track campaign conversion. 

I know from native to web there is the a query parameter implementation to override ECID - does something similar exist on native (without creating a new, higher priority visitor ID altogether)? 

[Jennifer_Dungan]

There is no out of the box solution... Adobe's solutions really only include adding the App's ECID to outgoing URLs for your web to pick up the value and stitch users who move from your app to web as the same ECID... but there is currently no solution the other direction.

That said, if you can append the ECID to your deep links, your developers might be able to force the app ECID to match your web identity?

I think because Adobe came up with the Cross Device Stitching in CJA, they didn't continue trying to investigate better user stitching on AA...  so I guess it's down to us to come up with our own creative solutions.