I know the numbers on the depth guages are just guides, but is 10 the deepest or the shallow setting?

It has the fiberglass seed hoppers, but no baffles. C
hecked a JD dealer and they did not list baffles for the fiberglass hopper, just for the metel ones.
Yetter shows baffles for their fiberglass hoppers.
Exactly how do the baffles control the seed flow? Could I use Yetter baffles on the JD hoppers?