Raw Image Extension (Microsoft)

Microsoft have updated their Raw Image Extension with support for Canon's newer .CR3 images*.

This extension works in both File Explorer and Directory Opus, for thumbnail and viewer support.

While Opus comes with its own Raw Camera plugin, you may find Microsoft's codec works better for some camera models (or vice versa).

More detail here on the forum:

Viewer/VFS Plugins: Raw Image Extension (Microsoft)

Note that Windows 10 (1903) or above is required.

* Edit: It turns out the CR3 update is only for Windows Insider build users at the moment, but will presumably be released for everyone in time.