I won't be able to celebrate for a long time to come. I have to support running an Outlook add-in in Outlook 2016 on Windows, which uses the IE11 rendering engine.
Just in case you haven’t heard: Microsoft recently announced that they won’t hold it against you if you drop support for IE11 in add-ins. Your customers might still complain, though.
Incorrect. For those add-ins, IE11 support was required until recently, and there was a real review process, and it was actually pretty good. They even reported very subtle IE11 visual bugs to us.
https://docs.microsoft.com/en-US/office/dev/add-ins/develop/...