That issue is actually why I went with a distributed approach to news:yc. Yeah, it's a pain: no remote updates (App Store restrictions) and a lengthy review process for each change needed (do you know about how often the markup changes, btw?), but I don't have to deal with any caching, rate limiting, or anything else this way.
(Of course, I don't even think you can do anything like that on the web (even JavaScript, cross-domain issues), so your approach is probably required there.)
(Of course, I don't even think you can do anything like that on the web (even JavaScript, cross-domain issues), so your approach is probably required there.)