Clearly, your mileage will vary depending upon where you are. My experience was that it worked in a timely (within 5 days) manner. The initial request was rejected, the missing information provided quickly, and an acceptance received almost immediately. Some consular official was listening! However, I have heard differently. Perhaps it is the specific consulate to whom you are farmed out to that makes the difference.
I have also heard that a ticket need not be in hand -- just knowledge of the flight arrival information -- but I had a ticket in hand, as I think most people would. The two-stage process COE, in my view, made more sense.
I would add that on arrival at BKK that no one -- no one -- checked the iPhone data, only hard copies. So, OP, take those along!