This is really interesting, as I too wish too watch SPECTRO from Main Street before going up to the dessert party.
So do you think it is bett just twatch SPECTRO and arrive for the dessert party 'late' (I was told by CM that they hold your res for 20 minutes past the res time - so that would mean we could watch spectro without losing our pre-paid res)
OR
Is it best to check in first, then go and watch SPECTRO? Although this would be tight as Spectro is 8pm, and my check in is 8pm, so It would be a quick dash to get to Main Steet before the parade reaches that part of the park - and hope there is a viewing spot.
Finally - do we all need to check in, or can one person do it for all of us. Iwas thinking about getting a viewing spot on MAIN STREET, then one of us poping up to check in, saying that we would all be up shortly - so at least they knew we were coming.
We are not a greedy family, so as long as desserts run throughout the buffet (8pm until 9pm) as they should, then this would be fine for me - I would not be piling my plate up, and just taking what i intended to eat, then go back for more I so desired.
Finally, just an opinion, but if a cast member said to me that all the buffet might be 'gone' at 9pm, and I had a 9:05pm reservation, then I would complain and ask for my money back - I would also report the CM for being awkward and ridiculous. It seems that he/she was just trying to put obstacles in your way.