Absolutely love the new additions to 1.13... I am with the rest of you and wish they would have addressed Mass Hysteria better but hopefully next release!
The one 'bug' I have found is when shooting a mode start on the right ramp and the ball DOESN'T fully orbit around to the left side, the stop peg still pops up. Before 1.13, that peg would only pop up to catch the ball if the ball was going to travel around the orbit, but now it pops up no matter what, even if the ball goes into the bumpers.
The peg will go down as normal once the "intro" to the scene finishes but you just have to make sure not to try and hit the left orbit until it does!
This is on a Pro, fwiw