As has been said above it's notoriously difficult in many twin aircraft to climb and accelerate in TO config with a windmilling prop.
It’s not notoriously difficult - it’s impossible. I’m yet to fly a light twin (and I’ve instructed on many) that will climb on one engine with a propeller windmilling - at any altitude or temperature or weight.
Airline category turboprops are the same. At max weight they go up at 6-700fpm OEI with autofeather. Fail the auto feather, and they descend at a minimum of 300fpm even when empty.
As sure as the night follows day,
more Aussie pilot’s lives will be lost in the future in these bull**** training accidents.