Some people have different pitch curves in idle up and throttle hold, some people use symetrical curves in all modes.

So the only reason to hit throttle hold if the engine dies is to get to a different pitch curve. Frankly I set mine the same in all modes so if something happens I dont have think (always a good thing) and don't have to play with switches.

PM me your email address and I can send you a draft of a how to I'm doing for the magazine section on auto's.