I'd like to share information about disabling Power BI Report Server Telemetrie with you.
You may have already expected that sometimes you receive a message when opeing Reports WebSite where opening a site at "az416426.vo.msecnd.net". So I've spend some time to get a deaper look in this topic.
Using IE Developers Tool and seeing script
After I check Telemetrie Settings within API via PowerShell:
For deaktivation you need to navigate into Windows Regitry and edit two entries.
After changing CustomerFeedback and ErrorReport from "1" to "0" for disable I ran PowerShell again.
After changing Regitry setting API request looks different.
After that I did several runs of Internet Explorer with Developer Tools ans request about "az416426.vo.msecnd.net" didn't occur so far.
Another thing I've expected was, that this only occurs when your systme has an active connection to Internet. When I disconnet my test system from Internet, request wasn't performed.
Another thing I've expected was, that when you perform an upgrade you need to re-check registry entries. After upgrading Report Server from 2018-08 to 2019-05 entries were readded to registry. Therefore you should add checking registry to your upgrade tasklist to keep it disabled.