Open with Explorer - When using chrome - Users always complained about having "Open with Explorer" feature enabled, as they are working on SharePoint libraries, it makes it easy for the end user to easily switch to Explorer mode, rather than switching the browser from chrome to IE. With the new Edge chromium browser, we anticipated to see these features working. To gain more confidence from customers, this feature needs to be enabled.
Export to Excel - Even though the feature is available in the library's SP ribbon, when you on the feature, it prompts with message "To export a list, you must have a Microsoft SharePoint Foundation-compatible application.". It would be very helpful to see this feature working on the new Edge browser.
Functions that are dependent on ActiveX and work in Internet Explorer 11 will also work in the new Internet Explorer mode in the Chromium-based Microsoft Edge. We announced this feature earlier this month, and it should be available for you to test soon.
We're glad you're testing, and look forward to your feedback on IE mode!