I think the proper way to fix this would be either to escape *before* creating the MediaUri as you suggested or to escape each parameter individually in the MediaUri object before reconstructing the URI string (that way the param delimiters won't be escaped).
I think the proper way to fix this would be either to escape *before* creating the MediaUri as you suggested or to escape each parameter individually in the MediaUri object before reconstructing the URI string (that way the param delimiters won't be escaped).