We just got back from a 10 night, triple split stay at All Star Movies (1 night), Fort Wilderness (6 nights), and All Star Music (3 nights).
At Movies, someone knocked on our door at 8:00 AM and then at 9:00 AM. We were only there one night, so I wasn't expecting anyone. I'm assuming it was actually housekeeping and not a room check. We had a late night at DAH and we're sleeping in. Regardless, next time I'll put a do not disturb sign on our door to see if that helps.
At Fort Wilderness, we had someone stop by our cabin one afternoon on our 4th or 5th day. He asked if we needed anything or if we had any concerns. I have no idea if someone stopped by each day, but we weren't around or noticed if anyone else did.
At Music, both afternoons someone knocked on our door. The first day when I answered the door, the CM went all the way into the bathroom. The second day, my son answered the door. The CM didn't come in at all.
Although it was a bit annoying, all the CMs we encountered always knocked. There was never a problem with one just walking in.