That would work (and personally I would prefer if AMP went in that direction) but it would be merely fast instead of crazy fast because apparently prerendering is only possible if you use the Google CDN.
Why? Chrome has been prerendering pages on search results for years. The only thing I could think of that would make it slower is that you may need to do a DNS request for a different domain, where google's domain is already resolved. (And google probably has a better CDN.)