A couple of points about the engine ratings etc.
Jim, I may be wrong but I would guess the reason the AB-139 does not have a 30 second rating is because it uses the PT-6. Generally the engines with 30 second ratings have new technology materials (such as single crystal blades etc) and I doubt that even the -67 version would have this.
The point made about FADEC controlled engines limiting power at the expense of the airframe is a bit misleading I feel. For the type I am familiar with (EC-155 which has dual channel FADEC and no cockpit engine control other than a switch) when operting in twin engine operations (AEO) the FADECs will normally control the engines such that they remain within the normal AEO limits. However, that is not to say that they will respect the transmission limits and so it is still possible to 'overtorque' the MGB to prevent mishaps. If this proves to still be not enough power to prevent the problem, and continued application of collective results in the Nr drooping, the FADECs will abandon the AEO limits and apply the OEI 2 minute limits.
If this still proves insufficient then tough!
The point I feel is misleading, though, is that this latter case is no different to a conventionally governed engine where if you pull in a big handful of collective, both engines will provide power up to the maximum contingency rating (2.5 minute) but no more. It's the same situation. The difference is that one limit is applied through the computer whereas the other is the topping setting set mechanically within the governing unit (AFCU).
Now, if you really want to see a system with an odd priority, look at the B-212 where the AFCU is designed to save the gearbox at the expense of the airframe. If you apply collective above 104.3% TQ the AFCU will prevent the engines producing more power. In fact it's worse than that; because the AFCU is respecting a torque limitation, if you droop the Nr (which you probably will do to prevent a heavy landing) the N2 will drop and so for a given torque value the actual SHP will be less. So the situation will escalate.