Microsoft Edge is available on Flathub and since it is a Chromium based browser, you can use any of the available Chromium based browsers to test (for web development) and the result should be the same.
Microsoft announced that Edge will be released with Blink engine (Chromium) in early 2019. They didn't talk about Linux version yet and at this point only VM and Browserstack works.
Microsoft Edge will now be delivered and updated for all supported versions of Windows and on a more frequent cadence. We also expect this work to enable us to bring Microsoft Edge to other platforms like macOS. Improving the web-platform experience for both end users and developers requires that the web platform and the browser be consistently available to as many devices as possible.
With browserstack there isn't any need for VM or Dual boot. It shows Microsoft Edge on any browser. It will allow to test your local sites.
Till now, developers have been relying on virtual machines or PC’s with Windows 10 to test their products and websites on Microsoft Edge. To provide an easier way to test, Microsoft and BrowserStack are partnering to give developers a cloud based infrastructure to instantly test and ship great experiences on Microsoft Edge.
and about Local Testing Security:
Local Testing enables you to test local folders and internal servers. We use custom-designed Chrome and Firefox extensions, with WSS (secure WebSockets) to connect your machine to the cloud. WebSockets allows extensive interaction between the client browser and the servers and devices. To protect the privacy of transferred data during the testing session, we use WSS exclusively. WSS uses SSL over port 443 for transport and therefore only transmits encrypted data.
When testing an private server, we forge a connection between the server you have specified, and our virtual machines or physical devices. The mechanism is set up to forward requests and responses back and forth, and nothing else. Similarly for local folder testing, the BrowserStack cloud only has access to the folder mentioned during the setup of the connection. Our infrastructure cannot access anything else on your filesystem.