If the throttle response changing with voltage drop is a real problem, then 2-3 throttle curves should negate most of it.

Playing Devil's advocate, it just seems that we are allowed to spend countless hours and dollars striving to achieve mechanical perfection, but as soon as an electronic aid is mentioned it's time to burn somebody at the stake. It keeps the airframe designers/manufacturers in business selling new designs that "present" better but what about the embedded system geeks that need money too??