No really. If you eat at the dinner as well then you need to give ang bao. In the end, you are paying more than what you get unless your friend is really generous to give you more.
You will have no time to 'eat' at the reception. Whatever you 'eat' are fast gobbles down of water and easily swallowed type of food, probably cold.
7pm start u shooting cocktail hour of buddy buddy group pictures and couple welcoming guests
Then you shoot the first march in, then cake cut, someone probably gives a speech, you shoot that. then you have a small 30 minutes window of rest while the couple leaves to change but instead of eating cold food leftover by your friends at the table, you will be checking your noob shots for mistakes and try not to repeat again for 2nd march in. The couple march in again, pop the champagene and do the yam seng thing, then it's one freaking hour of table group shots, once done, it's on straight to the guests send off shots and more buddy buddy group shots. By then waiters already folding up tables. This what happens at common lower tier to mid tier weddings. So tell me, how much Angbao you wanna give to eat bits and pieces of cold food? How much the couple can save if they do away with your seat?
Half the people dishing out advice here have no real pro wedding photog experience.
Charge your friend at least $70 per hour. And don't bring anymore photog friends. It just take away more control from you and increase chances of things going out of control and failed expectations.
Either you do it right and pro, or you don't do it at all. Sorry, no midground, and mid ground is the most dangerous game to play.