I keep my chipbreaker about 1 mm back from the blade edge, and on woods like oak and cherry it works fine. While planing ipe I noticed fine chips/sawdust accumulating just in front of the chipbreaker (NOT between chipbreaker and blade). Generally, plane was generating sawdust, not shavings and was noticably harder to push. So I moved it back to maybe 2 mm, and all of a sudden, I was making full-length shavings and the force needed to push the plane dropped drastically. Went back to white oak for a check, and the difference wasn't nearly as pronounced.
So, are there some guidelines for setting chipbreakers wrt wood type? FWIW, Ipe is harder and more crack-prone (stiffer???) than oak. (Shavings are much easier to break than oak ones.)
The plane is a Record #4 with a PMV11 blade (and original Record chipbreaker, ground down and polished to close any gap w/ the blade). Blade is honed to 8000 and works just fine on white oak.