Microsoft has published download links for Edge Insider Preview channels for Windows 10X and HoloLens 2. The links appear under the 'Other platforms' section on the download page, and also exist as an option for supported channels.
Windows 10X as a special edition of the OS that was initially designed for dual-screen PCs. Microsoft is about to add some of Windows 10X's features to regular Desktop editions of Windows 10 on order to get the best of two Windows branches. The company may also replace some of the Desktop feature updates with Windows 10X releases. Microsoft's latest plan calls for 10X to debut on single-screen devices designed primarily for businesses (especially firstline workers) and education in the spring of 2021. And in the spring of 2022, Microsoft is aiming to roll out 10X for additional single screen and dual-screen devices. Windows 10X is expected to have blazing fast update installation on the classic Desktop devices and container security protection for Win32 apps from Windows 10. Reportedly, the initial public release of Windows 10X won't include Win32 app support in any form.
Starting today, the Edge Insider page includes downloads for Windows 10X and HoloLens 2.
The link points to MSIX packages that can be installed inside the Windows 10X emulator or, in case of HoloLens, on the appropriate device. Both environment do not support classic Win32 apps, so the MSIX wrapper package is the only way to get the latest browser version installed there. MSIX builds are available from the Beta, Dev, and Canary channels.