Not to derail your question, but when did you set the appointment for? I need to set mine for the 17th or 21st of September, but when I called on Monday he only had appointments open up until the 9th. I want to be sure and get my call in as soon as they open up!
Just based purely on what I know, I would really doubt that having an appointment counts as "in process." I would think it would only be "in process" the day you either attend your appointment, or your application has entered the processing stage if you post it. After all, an appointment could be missed/changed, etc.
At this point I'm leaning towards taking my chances with the cap rather than waiting a possible months on end getting my postal application completed and being unable to look for jobs. But seeing as how none of us knows anything, it's a huge risk I'm taking.