This option is great for connection to older hardware which Edge doesn't support and fals back to IE mode.
like for older HP-ILO , IP camera's, older switches.

If needed, enable older TLS1.0 and TLS1.1  through ControlPanel / Internet Options / Advanced Settings 

Create a sites.xml, see example

Copy the sites.xml in C:\Windows

Add this to your registry:

Reg.exe add "HKLM\SOFTWARE\Policies\Microsoft\Edge" /v "InternetExplorerIntegrationLevel" /t REG_DWORD /d "1" /f
Reg.exe add "HKLM\SOFTWARE\Policies\Microsoft\Edge" /v "InternetExplorerIntegrationSiteList" /t REG_SZ /d "file://C:\windows\sites.xml" /f

In Edge itself update the settings instead of restart with:

edge://compat
edge://policy

The sites in sites.xml will be displayed in Internet Explorer Modes when typed in Edge.