How does it support Windows if not with Miracast? Is it just 'support' as in 'casting' (playing media locally) as opposed to actual streaming (eg. cloning) of the display?
You can mirror the whole display or a chrome tab, but you need to use Chrome's extension for that. It streams via Cast protocol, not Miracast.
You can cast a chrome tab, so it actually supports streaming. They're just protocols, why do you need to support Miracast for it to work on Windows?
I'd like to actually have a wireless display. AFAIK, the official mechanism for that, on Windows, is Miracast.
EDIT: Sibling comment says it's also supported via a Chrome plugin. That might be an option...