why does 2006 F250 have 2 different water pickup locations?

What purpose is the normal lower unit water pickup and the addition of a set of pickups at the centerline of propshaft at very fore foot? After taking water pump apart this week and trying to replace bottom stainless plate with 2 cuts in plate? I would say yamaha is trying to move more water through system? Did the 4 strokes ever have a overheating problem that I was not aware of?

[boats.net]

It is to keep a steady flow of water to water pump, I didn't have any issues with them before or after change.

[TimS]

To sell you a special flushing attachment? Or do the standard muffs work OK?