So like. If a speedrunner has 8 people in a party (All in a party) and then go into a game of Party Games. He/She can have them just die or complete the game if necessary. For example "Bombardment" All 7 players can fall off a cliff and complete the game in less than 10 sec.

I don't know, there isn't a rule that has been made for this yet. Maybe we should add a variable for whether you're in a party or not and add it as two sort of seperate categories?

You could add a separate categories. Or we could put a limit of max 2- 3 people in a party.