In case anyone is curious, I entered my room request in the room finder yesterday afternoon. It sent at 8:18am Eastern this morning, per my Dashboard. So they must batch those emails and send them the next morning if you are within 30 days.
Also, here are the four sites I was scouring for dedicated reservations. I have either seen good reviews of them online (DVC Rental Store, DVC Shop Rentals) or used them myself (David’s, DVC-Rental) with satisfactory results:
There are many more. I looked multiple times a day over the last month and while deals came and go, it wasn’t until 5 days before my trip that the perfect reservation popped up, saving me over $1K.