Reg,
This is the setting I used to use.
I now use the minimum gap on my Valley for wheat and one back from that for all other grain.
I do get a lot of flour from the crush, but I have a mesh bag that I put over my MLT manifold. I don't then have a problem with a stuck sparge, and I get higher efficiency too.
So start experimenting, it won't hurt.
Beers,
Doc