Bill Houghton, Sebastopol, CA
Since the chipbreaker (at least the classic Stanley Bailey* chipbreaker) has only so much "length" as it curls down onto the cutting iron at the edge, if you try to camber the chipbreaker, you stand a chance of making a gap between breaker and cutting iron, something you don't want, as it will catch shavings.

*And Bailey clones by other makers after the patents expired.