When I generate my mesh my whole bed is showing below 0 in the Z plane. What information is this telling me? What does Bed Visualizer think is 0? Shouldn't 0 be some kind of averaged midpoint?
It all depends on what is returned by your firmware and if you have the option
Use Relative Z Offsets enabled or not. That option does kind of what you're asking but doesn't use an average but the lowest point if I remember that's how I programmed it.