Good point Checkboard, I still remember my first post twin rating flight, in a Twin Comanchee,having trained on a PA23.
The practically non existant rate of climb on one engine is startlingly clear in my mind over 20 years later, as is the picture of the tree tops we were skimming over.
I should add that the assymetric condition was part of the type familiarisation, not for real.
The experience has made me think carefully about the desirability of flying marginal twins.
However the problem posed was single engine climb in extreme temperatures, so the turbo suggestions probably make sense.