The cascade breaker should be off as soon as you are rank 1 in PVP (gradually in fact). There was a bug before the 3.0.5 which resulted in an advantage for the player:
We still didn’t have any details about this cascade breaker… I’m not sure the difference between 3.0 and 3.0.5 is only due to the correction of this bug. In all cases, it means that devs can well manipulate the board (ie gem drop) as they want…
I believe that there is also a bug with the loop breaker which triggers too early…