x2 bad tuning kills em.
If you get det, in-cylinder pressures might go from 1000psi to 2000-2500psi suddenly, if this happens BTDC then Mr Rod has huge stresses on it.
As long as you make sure that peak cylinder pressures are reached 8-20 deg ATDC you make best power, so if the tuner doesn't get too cute with advancing things beyond the ability of the fuel to produce a smooth flame front then there is no reason you can't stuff more boost in.