Ok, I give, I am looking at POH's and maintenance manuals for the D, E, FF and N models and no where can I find where it states you "MUST" flip the pedals or even suggests that you do flip the pedals. Help me out, where in the POH or in the maintenance manual does it state you have to flip the pedals after shutdown. If you look at the rigging, flipping the pedals actually puts stress on the spring and by leaving the pedals as they are, the spring is under less stress.
The rigging is suppose to be set so that at Max continuous power, the pedals will remain neutral if you remove your feet. This is done with the over riding spring. Why would flipping the pedals and putting tension on the spring "keep a strong spring"? The spring should be the closest to relaxed when the pedal is full left such as shown in the picture.
I can not imagine what bits you would be pounding while sitting. Naturally, you would prefer neutral on start up and shut down but sometimes a little right pedal will help getting N1 up if it starts to hang or become slow.