I was reading this question about regularly turning the engine off by dropping the clutch in first gear. This is fairly obviously a bad practice, and the answers give great reasons why, but it got me thinking: are there any adverse effects to turning the engine off with the transmission in neutral and the clutch engaged vs with the transmission in neutral (or in gear) and the clutch disengaged (pedal to the floor)?
I was thinking that with the clutch engaged + tranny in neutral, you're still having to spin down the extra weight of the clutch & input shaft of the transmission, which would slow the engine down more quickly; whereas with the clutch disengaged, the weight needing to spin to a stop would end with the flywheel/pressure plate/TO bearing.
Would leaving the clutch and tranny input shaft 'attached' be enough extra drag to cause even the slightest wear on any part of the drivetrain? This is all assuming the vehicle has come to a complete stop.