I love the method. I especially love the fact that the method is linked to visualization; to immediately make the outcomes more discernible.
I’d think there’s an opportunity for two levels of analysis using color: one that utilizes hue, another that describes saturation. For instance, when visualizing the data, hue could represent the person who experienced the expected issues, and saturation could represent the amount of people who experienced it in the first place.
Or, it could represent the magnitude of problem the design flaw causes.
Or, whatever you like. Keep doing your thing!