I was there for the taping last year. THe time slot I was given was for Friday morning, early...about 7ish. They sent us to the Castle forecourt where we were supposed to be the audience for the forecourt shows. I got tired of standing in one place after 3 hrs so left. But, I understand that they were pretty much done with that part by 2ish. There are other spots around the parks where they may be taping specialty acts/singers or such for the Christmas show.
Then, on Sat, they taped the actual parade. You can get to the other areas of MK if you cut through the shops. Main St. is pretty much taken up by those who were given that time slot, by preregistering, so if you just walked up and tried to sit on the curb, there wouldn't be a spot. This part of the taping can go on for a very long time, but was over by early afternoon I believe. I headed to MK around 4ish and there were only sporadic tapings going on in different areas but not of the parade anymore.
Sunday isn't a big deal at all. So.....if you want to go to MK on taping days, go early in the day, while people are still actively involved in the taping. As they get pooped, they start to wander off and head for the attractions.
I'm just glad I don't arrive until the following week....did the taping once, don't need to do it again.