airfoilmod,
sorry for being obscure.
You said in your post that both actions (max. thrust, and idle thrust) were to avoid ice build-up.
They aren't.
One was supposed to avoid it, the other to remove it.
And I also can't see how max thrust brought any aircraft into trouble. It was only that max. climb thrust (which is usually on the order of only 30% of maximum (takeoff/go-around-) thrust) didn't keep them out of trouble.
Or maybe I misunderstood the first part of your post.
I get the point, as does the NTSB, that the idle melting procedure is not optimal, to say the least. That is why the Trent 800 FOHE design is being changed. It may take a while. What to do in the meantime? Obviously I have no answer to that.
Bernd