"If you play not solo then all players must complete the game ans survive.

On The Island, Aberration, Extinction, Genesis Part 1 all players must get the cutscene plays after defeating final boss (Overseer, Rockwell, King Titan, Corrupted Master Controller).

On Scorched Earth, The Center, Ragnarok, Valguero all players must survive on Arenas boss fight (Manticore on Scorched Earth or Broodmother and Megapithecus on The Center or Manticore and Dragon on Ragnarok or Manticore, Megapithecus and Dragon on Valguero or Moeder on Genesis Part 1 (Moeder))."

So the run would be invalid if anyone died in during the boss fight?

The run would be invalid if anyone died in during the final boss fight. IMHO, Yes. Because solo player can not die in run. All players must be in an equal conditions. I think solo players have a harder time playing. They can carry more weight (more guns, ammo, healing brews). I think dead is not big problem. Much more dangerous is game crashes. This should be discussed.

But. For example. If one player died on the Island on Dragon or Megapithecus or Broodmother, he can go to Tek Cave because that bosses give you trophies (You do not need engrams). You need trophies for opening Tek Cave door. Do not matter, who died before Tek Cave. But all players must complete map.

Let's look at all the options.

1. If a solo player dies on an ascension or a boss, then speedrun automatically goes into the trash.

2. A group of players is much easier to speedrun.

But. There is a problem. If one of the players crashes the game at the time of the ascension, he will not be able to complete it. This is a game issue, not a player. What to do in a similar situation?

There are only 2 options.

The first is my decision. It does not solve the problem with the crash of the game. But it is fair, as I believe.

The second is to allow speedrun to be completed for the last surviving player. Solves the problem with the crash of the game, but not completely (if the game crashes at the host - the end). Not fair for players with a smaller tribe size.