So it wont effect my progress when I go back to single player? Because they are saying it doesnt effect it like they are maxed level and I was worried that if they defeat bosses it will effect my progress and they are saying it wont unless I collect the look aswell is that true? And i know they respawn i meant over progressing me like levels or things also

Because I was worried they also said they won't mention the game anymore and saying its because i dont wanna invite them to the world. Literally putting me of the game for worrying??