I think all the meets we've been to have had electronic scoring, so we've never had to wait for anyone to actually add. Typically awards start the second the last team makes it into the room. Some people just take FOREVER to announce though. Sometimes there seem like 100 age groups. (Which you might not think takes longer because it's always 50+1 and 100% AA that get awards, but it does, because of the time to announce event and age group and salute for a minute so people can get pictures, etc.)
I have been to two events where a gymnast was left out and they had to re-calculate for 20 minutes and then completely re do awards.
I have been to one where a whole gym was getting their mobility score and had been really up front about it, but at the awards they started, "realized" that that was what happened, stopped awards, spent a freaking HOUR putting that team in their own "age group" and then redoing awards. (They were pretty awful to that team about it too.) There were only three teams, them, us (big team) and another (tiny team). So we ended up competing against ourselves (which happens ALL THE TIME with a big team) and they screwed up the new age groups too. They should have just left it. The score out team was competing routines 1-3 levels above ours, with the resulting deductions so the awards really were shaking out fine.