All I know is, is that until sentry sniping is fixed, I’m done with Incursion. That crap happening once is enough to make me not want to play for the rest of the day. Nothing worse than pushing minions and whittling down a sentry, only to still be losing to a team stuck in its base. And it’s not like I can just stroll in leisurely and kill him either. Yeah, try shutting him down as Attikus or Boldur. Hope you can come up with a better strat during respawn.
As for back dooring, if the sentry or turrets can’t hit you, and the most you have to do is hold auto attack, then yes, it is an exploit. There is no real risk once you set up camp. 1 character shouldn’t be doing what a team + minions attempts to do.