Add ability to request return wkid from wms services

A request to allow essentials to provide a user set wkid to outgoing requests to wms services such as image servers (express server, image web server).  Currently when using a viewer with arcgis online or bing base maps, outgoing requests to image servers include a request to return the image in 102100 (the wkid of esri's base map caches).  At least some image servers don't recognize 102100; however, they do recognize 3857, which should place correctly on web mercator auxiliary sphere (102100).  I noticed with esri's flex viewer, the wkid of outgoing URL requests is configurable in the xml code of the viewer regardless of the viewer's actual projection.  Might it be possible essentials could have the same functionality with a user defined wkid parameter similar to how the wkid for measurement can currently be set (for the silverlight viewer at least)?