I have quite a lot time in the Aerostar 601P, the single engine handling was interesting but not as bad as rumours state.
Of course in any multi engine aircraft you always have the option to reduce power on the operating engines to maintain directional control even if that means landing ahead under control.
Anyway as the OP said let's discuss the reduced power take-off.
Skyhighfallguy
I echo big pistons forever, esp about cooling with extra rich mixture.
BUT for the Seneca V driver. How about this: you do a reduced power takeoff (climb power) and you lose an engine.
Do you add power on the good engine?
Your first action during such a failure should be to confirm or apply full power to all engines anyway.