I think a really cool Battle Royale game mode would be a Hostage game. So like just the basic idea of it would be 2 teams of say 50 players and the team to finish with the most hostages wins. So when you down someone you would walk up to them a hold a button to take them hostage. It would take a little time kind of like reviving a teammate. And you would have the choice to either kill them or take them hostage. Obviously if your taking fire you're better off trying to kill them. The hostages would be kept in a hidden unknown location that the hostages teammates could try to find to release them. Each time they get released the location changes. Once all the people of one team are either dead or taken hostage the game ends and whichever team has the most hostages wins. Just an idea.
Get where your coming from but kinda defeats the idea of the mode, BRs are last man standing. Respawns, in this case hostage stuff is going against this. Your goal is to kill everyone who is not your team, no exceptions.
Personally i feel BR modes are boring as they are just the basic map over and over, same stuff over and over. Only difference between each map is who got what first. Not to mention they were a fad that is slowly fading, look at the BR king Fortnite, its slowly losing popularity to the point it had to reboot to gain people back.
If they do add a BR mode, and i have a feeling it will be, just leave it the basic BR style. This game is meant to have so much stuff in it anyway.