I'm surprised you prefer a spring to cable tension getting the chain onto larger cogs, even though it allows you to pre-shift to a lower gear while stationary...

That reminds me of a 'high-normal' Exage (I think) derailleur I had once... the pinch bolt was on a little sprung lever, allowing the pre-shift to low. Puzzled how it was such a unique feature; it seemed to work well enough, being quite a strong spring.