This is the answer I was looking for. I discovered that if I go ahead and make the Connection with identityMap as the primary identity field, then I can create the Data View in CJA, the identity map seems to work as expected.

I don't see ECID mapped to another attribute.  I do see in the request payload the query.identity.fetch object that contains the value of "ECID". Is it possible the mapping is happening on the server side and I'm just not seeing it in the DataSet Preview? Am I correct in my understanding that ECID i...

Yes. All the XDM fields I'm pushing to the DataStream are making their way into a dataset correctly. But in the DataSets UI, when I preview the data, the identityMap field just contains a dash "-". I should expect some key/value pairs with ECID there, no?

I have a simple page I built to do some testing with collecting data via the Edge network using Alloy.js. The ECID seems to be getting set on the page correctly but when I look into the datasets, the identityMap field doesn't seem to contain the ECID. I also don't see the ECID or the identityMap fie...