As I understand it, you should not fill out the request section in online check-in AND do the TP email service because the online check-in requests will override anything.
I have gotten very close to what I requested and I've gotten nothing like what I requested.
A few tips...
First - When you select a room, the first line of the email will pre-populate with coding that the assigner understands and room numbers along a line. It's best to leave that as-is.
Second - In the section to customize your request, list NO MORE THAN 3 preferences that help explain why you're requesting that.
For example, when I was staying at Sports, I selected a room and left the pre-populated field as-was. I then said "I would like to request: 1st priority - Surfs Up section; 2nd priority - 3rd floor; 3rd priority - corner room". That way the assigner understood what I was looking for and could first look at Surfs Up, then see if any of those available rooms were on the 3rd floor, and then if any of THOSE were corner rooms. I was next to a corner.
If you just request a room, or even just leave the pre-populated field as it is without adding comment, the assigner doesn't know WHY you're requesting that.
Third - It's still only a request no matter how you make it. I had one stay at POFQ where I specifically requested one of the close to the main building buildings and stated that I was arriving late and being solo would prefer not to walk all the way across the resort in the wee hours of the morning. I have no way of knowing if I was never assigned a room meeting that because they typically don't send the numbers until you are checked into DME if you're getting there that way (or didn't at the time), but the desk CM has no way to see the specific requests or why a room has been blocked for someone else, so my strong suspicion is that I was moved because someone else complained about being as far as possible (the room I ended up with).