We expedited through Emma chat. During hours when agents are available, you type "live chat," then it give you a list of options. Select "Case Status," then you'll get in a queue to talk to an agent. They will ask what you want, say expedite your EAD, then they will ask you reason which has to be from a list. The most common is "severe financial loss". Then you plead your case and hope it's approved! Some people get immediate approval, some immediate denial, some get asked for evidence and some none. Unfortunately no way to know, but you can put in multiple requests if one gets denied!
We never even were told that ours was approved, just an e-mail saying they received the request and then they approved the EAD the next day.