changing the tire size will not so call fix your camber issue. First both tire size and camber including wear are all relative....a matter of degree. Increased negative camber which is a natural by-product of lowering will cause any tire to ride more on its inside edge. When you widen the tire, the inside edge is farther from wheel centerline and hence you have a higher magnitude of wear comparative to a stock tire width/footprint.
HTH,
George