Mike performed the same eye-opening hardness testing for me. I hit 54 HRC, but I was using a steel that I had a pretty good heat-treating recipe for. Another razor from that batch turned out to be a great shaver, so I concur with your conclusion that a blade doesn't have to be ultra hard to work well.

Heat-treating is about knowledge first, with control a close second. You need to know what you have to do, then you need the tools to help you to stick as close to the recipe as possible.

The first piece of knowledge you need is what results you're getting with your current process.

Josh