Great news! Acoustic Exchange and DDX are entirely compatible! Here is how tagging will work when you use Acoustic Exchange Capture.
When Acoustic Exchange Capture enables Acoustic Digital Analytics, DDX tagging is included automatically. Be aware that for an Acoustic Exchange Capture enablement, the library for the enabled application is loaded and DDX does not need to deploy any Partner Library enablement tagging for the application. As you enable tagging in oneSDK, the same tags should be removed in DDX. Similarly, as you add new partners to Acoustic Exchange Capture, their library loads have to be removed from DDS.
You can use Acoustic Exchange Capture to load Acoustic Experience Analytics and idSync as well and still load vendors with DDX and use it for tagging. Using Acoustic Exchange Capture and Acoustic Experience Analytics in conjunction gives you the benefit of a common session ID.
Acoustic Exchange Capture cannot migrate data from DDX as of now. Note that Acoustic Exchange Capture always loads DDX when it loads Digital Analytics. This means that you can migrate your data whenever you get a chance.