Those numbers are great and all, but you really need to consider the proper cooling of those engines. A standard rule of 2&2 or 1-in-1 works. Reduce the power 2"(1") every 2(1) minutes appx 10 minutes prior to landing. There some document out there towards the recommended operation of the GTSIO engines, but I can't find it. It basically states the above, and to never do aggressive power changes from high to low. Also avoid operating below 18" MAP in a decent as it unloads the gearbox and there were harmonics issues there as well.
As far as overboasting, doing a proper warm-up, letting both CHT and Oil temp get well into the green should do the trick, and also adding power in a smooth 5-7 second push makes it easier on them also.