Just to add some food for thought. You could have a wedge razor with half the spine thickness as a full hollow (assuming the same width) but the wedge still wouldn't really flex anywhere near as much as the full hollow despite a much reduced bevel angle and apex width, you also wouldn't get the same feedback. A lot of how we feel about cutting tools and how they work is not really bevel angles and apex widths but the geometry and mass of material BEHIND the edge. Once the apex has cut into the object it can't really do anything else, you're then relying on the geometry of the tool to complete the act. A good well defined apex is the pry-bar that gets you through the door but beyond that it has minimal effect.