Hi, what's the advantage of rendering markdown using Github's API? Is it just a way of staying on the cutting edge of improvements to their markdown rendering feature set?
In any case I've noticed that using online mode is quite slow as the preview has to wait for an API response. What if you were to render the preview immediately using offline mode, then replace the preview with the online response once it is received? That way you'd get a "good enough" preview as you type, and when absolute correctness is important, it wouldn't be a problem to wait a moment for the real preview to kick in.