Scavenger
Simple answer is they don't won't you to do it. It leaves them wide open to being sued if something goes wrong.
And I would think the engine monitor will not allow you to lop. To do it legally you will have to have an stc to cover you if it's not in the poh. The aircraft manufacture states what parrameters that the engine is to be run to and not the engine manufacture. Same goes for the maintenance of the engine. It is the airframe manufacturer that take pressidence over the engine manufacturer. Ie they set fuel flows rpm prop angles etc etc.