the last thing of your sentence isn't true anymore: https://docs.microsoft.com/de-de/office/dev/add-ins/concepts/browsers-used-by-office-web-add-ins https://doc

the last thing of your sentence isn't true anymore: https://docs.microsoft.com/de-de/office/dev/add-ins/concepts/browsers-used-by-office-web-add-ins https://docs.microsoft.com/de-de/office/dev/add-ins/concepts... it really depends on your platform/version. Keep in mind that they try to use chromium in 2020.