The final answer was on the forums.asp.net forum that you contacted in your original question. These answers came directly from the product group members themselves. Cookies auth / cookieless are obsolete technologies. Nothing of the ASP.NET team has been supported in recent years (MVC, WebAPI, SignalR, Friendly URLs).
Things may work by a fluke, but this should not be misinterpreted as an officially supported script. All errors that have been filed regarding cookieless forms of an auth / cookieless session are automatically resolved "will not be fixed" by product groups.
Levi
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