Correct VSync is not switched on in the beta, either lock your monitor's refresh rate to 60Hz or (better) go to your GPU settings and switch on VSync for pinballarcadedx11.exe (note - this only works in fullscreen mode, use Alt+Enter to force fullscreen).
I've been looking around, but thus far been unable to find how to set things for individual programs (thus far, everything I've tried has been for broad settings). I seem to have got the V-sync to lock for the game at full screen, however, it seemed to have locked at 30FPS (a bit lower than I'd like naturally).
As for Refresh Rate, it seems to be set at 60Hz, but I don't know if there's something special I need to do to lock it at 60Hz (not sure if set at 60Hz is the same as locked at 60Hz).