All the sections have a good view. And people are always free to go stand at the railing too, or walk back and forth,
I'd tell the CM over the phone to note it on the ressie.
More importantly, I'd explain it to the CM when you check in. In case the phone ressie person did not tell you (or got it wrong), the party starts 1 hour before the fireworks that night. But you should be at the Tomorrowland Terrace 15-30 minutes before the start of the Party. A CM there checks you in and gives your entire group wristbands, then lines you up. At the time the party starts each group is escorted to their table in the order that they checked in.
When I made my ressie the CM on the phone told me my ressie was for 9:20. I thought it sounded odd. We were in the MK one evening while the Dessert Party was going on (several days prior to our ressie) so I went over and asked. The CMs actually working the party were appalled that I had been given such bad advice. But since then I have seen several other people on this board who were told the same thing. If you don't show up until 9:20, you'll have missed a big chunk of the time you paid for. And just maybe they'll have given your table away to a walk-up by then!!!