I searched thru all the similar questions here in stackoverflow but there was no mention on how to manually set compatibility mode for the IIS Express - Edge (from VS). I'm not talking setting in web.config or via aspx page, but manually from the browser.
On a deployed app (to IIS 10 web server), I can test via MS Edge manually setting and unsetting compatibility mode but no such option seems to be available when working localhost IIS Express - Edge from VS.
This issue was resolved by changing the "Script Debugging" to Disable. Once that is performed the compatibility option will appear in IIS Express Edge.