Not sure about the 2.3 MZR but in the 2.3 DISI MZR the rods will bend somewhere near 30 psi of boost, assuming fueling is good. A lot of un/improperly tuned cars will vent the block (stock tune with heavy modifications like intake and downpipe).
As for output:
I later added 6 degrees of timing to this tune (as my targets were not hit) and managed another half pound of boost or so up top. Rated stock flywheel output is 260hp / 280tq; I've also since added a real downpipe to the car (which frees up a LOT of exhaust flow) and will be adding an intake manifold (which will correct the flow imbalance between inner/outer cylinders) along side an air/water intercooler (which will drastically improve flow and gain 2 psi or so efficiency from the turbo). That should put me somewhere near 320 hp / 400 tq, all said and done, with no modifications to the stock longblock.