Using AJAX'ed HTTP requests from an App I found that when I send a HTTP status error from my web service, e.g. 400, the proxy ignores this and sends 200 OK.
The proxy should forward any HTTP status code returned by the external web service. Not doing this makes error handling more complex in the App. The AJAX ".fail" event is reduced to a "proxy_fail" event, and not a service fail event, which I think should be its purpose.
BTW: Thank you for an otherwise great App framework!