I cannot wrap my head around this one... I've a hosted feature layer (WGS_1984_Web_Mercator_Auxiliary_Sphere) added to a simple Web App (built via WAB). Using the select widget and the attribute table widget I can select points from my hosted feature layer, show these selected records in the attribute table, and export the selected records to a CSV. During the last step, both X and Y attributes are appended to the end of the CSV. Here's the glitch: at first (as in maybe the first 3-5 times I export something from the app) the x and y fields are calculated in decimal degrees. From there on out, they are calculated in meters. This makes sense, as the documentation describes the output being tied to the feature layer coordinate system's default units regardless of the map's units (Attribute Table widget—Web AppBuilder for ArcGIS | ArcGIS).
All of this led me to the following feature request:
Please up-vote so I we can all control the output units and coordinate system. Perhaps with functionality similar to the Coordinate Widget (with defined transformations, units, and so-forth).