I just tried this on a whim, and I actually managed to do a decent job of sharpening an edge through bumpmap painting. That's pretty neat. Unfortunately wireframe mode is broken right now so I couldn't get a wire overlay, but the whole ridge is about the same smoothness all across, from a geometry standpoint. I just went over the middle section a few times with progressively smaller bump brushes to make a pyramidal mini-ridge.
One drawback is that uv seams usually end up in corner areas like this, and that can mess with the bumps a little bit.