Remember the Rich Franklin All Access episode? Those insane weight room marathon sessions? His trainer's philosophy was "Rich fights 5 five-minute rounds so we do ten 10-minute rounds so he never ever gets tired". Did it work? Was Rich in great shape? Sure. But you gotta think if it was worth the time and how much it taxed his recuperative ability.
The truth is if you fight 5 minutes at a time then you should train 5 minutes at a time in fight camp. Going longer changes the energy systems you're using. You'd be better off resting less than the allotted 1 minute then you'd be training more than the 5 minutes.
In the late 2000s a fighter and S&C coach named Paul McVeigh experimented with fight camp S&C training and anecdotally found that less was more in terms of volume. And it didn't matter much what modality he used, he just had to work hard for the 5min on 1min off format. Urijah Faber, Randy Couture, and others have echoed similar thoughts.