as long as that backup is not being used in between a series without a valid reason. at max, one series can be 5 hours. indoor game and now most teams are bootcamping. i dont know why someone needs to be replaced in between a series.
that vitality move of playing nivera on some maps only annoyed me the most. its like easing the workload by making players work hard on only a couple of maps. that is killing the professionalism of the game.