While I often use lapping film rather than stones, I do use my coarse stones a lot for edge repair and bevel setting. Usually I don't hone just one razor. I will do a batch of 10 or more. So, my coarse stones get lapped before every major session. Like @thp001, I try to minimize or eliminate overrun. Tiny little details can add up incrementally for a (maybe/sometimes/sorta) noticeably better edge. At least that is the theory that my possibly placebo effected brain works on. I agree with @PaulFLUS that honing in hand is a great way to keep the pressure balanced and regulated. Heel hooks? We know how to deal with heel hooks. Remove the heel! But a good X stroke with a good heel leading angle helps prevent them from forming.

@Euclid440 is right. First grid lapped away, only indicates flatness if it is ground off in just a few laps. I generally go a second time. The second go at it usually does get the grid off in just a few laps, and then you know it is pretty close to dead flat. I actually don't always draw the grid, for the first round. You can usually tell when you have a new fresh surface showing, without a grid.