I know I'm probably the only one but I really wish they'd have Dev Tools that you can use on the device instead of remote debugging. Especially on Tablets and Set-top boxes.
I believe a horizontal swipe could show or close the tools. That way you can still select the element in the content window and look back at the source. Since non-developers might get bogged down with it I'd suggest it be option you tick on in settings.
I've made quick pushes via web IDE on my phone while commuting. I doubt improved tooling would increase frequency, but it would certainly increase the complexity I'd be capable of and my confidence in not pushing janky brokenness.
Since Firefox OS and Firefox for Android run the same engine its very easy to switch between them to test stuff.
http://moduscreate.com/enable-remote-web-inspector-in-ios-6/