I do think we have ability to get a point of presence in China, but it would take an enterprise level contract to set up since as you know it requires a whole lot of work (setting up a local office in China, working with Alibaba to set up a node internally). I understand that is not what you are looking for, just wanted to put it out there that we have investigated the possibility and determined that we could do it, given the return on that investment (and it would have to be limited to single, pre-qualified clients as you know from researching the ICP).
What you could do today for 0$ is something like use a geo-redirect (Redirect options | Netlify Docs) for assets requested from china to point to your other destination from Netlify; it means the first request would be slow but you’d HTTP 301 them to a content source inside of China which would presumably be faster. Or, if it isn’t reasonable to do that “at the same hostname”, you could use that feature to instead 301 redirect Chinese requests to an entire separate website that is hosted off Netlify, within China, for that Chinese traffic. These are both workflows we can provide tech support for.
You could also use some DNS service that supports geographic based routing, like NS1: https://ns1.com/geographic-routing - this would let you return a more-local response to DNS lookups in China rather than your Netlify record(s). While NS1 is our DNS provider, we don’t expose that particular feature to you in our DNS hosting, so you would need your own account there to configure it, but we use that feature for our running our CDN and it works quite well.
Note that proxying TO Netlify is not a recommended workflow as it often fails and we cannot help troubleshoot when it does (see [Support Guide] Why not proxy to Netlify? for details), so I can’t recommend that, though it might suit your needs better in terms of response time - we can’t make a lot of guarantees about your site working well that way 
Let me know what you think!