A way of automatic installation of extensions
All other major web browsers (Chrome, Firefox, and Internet Explorer) provide some way to install an add-on/extension by the application installer. Most antivirus programs and download managers make use of this capability.
With Edge, the end user, after installing the main application, has to go to the Store and add the corresponding Edge extension manually herself.
There should be way for the extension publisher to obtain Microsoft-signed extension package from the Developer Dashboard, and include it along with the main application installer, to be added later to users' systems by powershell's Add-AppxPackage, or its equivalent.