Send to Chromecast Audio from watch

Hi there,

I'll start with an admission that I have not yet tried this. I'm willing to do the work if I know it's possible, but I want verify its plausibility before purchasing and diving into complicated configurations. Also, if it's already been done, I can save myself the work

I just got a Huawei Watch and want to be able to initiate a cast to my Chromecast Audio from my watch, without having to pick up my phone. For example "OK Google, play Jason Mraz on my Chromecast" and music starts playing from Google Music to my house speakers. The voice piece is also optional as I'm willing to have an app or "scene" or something on my watch which has a button that just initiates a cast with whatever is already playing on my phone.

I imagine this will involve some complicated combination or Autocast, Autowear and maybe Autovoice. Any ideas on if this is possible and where to start?

David