Just create servers that consume AccessibleHTML, and then adulterate it into fancy regular HTTP/HTML for consumption by most UAs (or, optionally, leave it alone for consumption by UAs that send a `X-Rendering-Policy: AccessibleHTML` header. Either way you can still get at the "real" AccessibleHTML source by sending `Cache-Control: no-transform`.) Think of these as "AccessibleWeb to RegularWeb gateways"—except they'd be deployed as reverse-proxies, so RegularWeb users wouldn't have to know they were there.

This is similar to the driving motivation behind RSS: it was supposed to be something for simple static sites to put up, such that gateways could then poll it, before turning around and doing something more technologically-complex to actually deliver the events, like using WebHooks, or sending emails, or doing whatever PuSH does.