I am running the latest version of collector paired with an external antenna tracking L1 and L2 satellites. I am only able to see WGS 84 coordinates for features I collect. Am I able to obtain an elevation while using collector or is this app limited to only 2D?
Have you tried the beta version of Collector? I don't think it stores elevation exactly where you'd want it yet, but I believe it will capture altitude data in a metadata field for a point.
https://blogs.esri.com/esri/arcgis/2016/05/03/collector-for-arcgis-10-4-beta/