I don't get it in full, but to me if possible seems more clear than focus peaking.
Maybe is because of the example posted, but if the dof lines are draw on the floor one can figure out if a vertical thing is in focus even if it crosses focus lines, no?
But I think that g3gg0 is right, if we use the lens focal distance it will be unreliable, a graphical DOF preview in Overview option could be better, to simulate what wolf sad about Hasselblad lenses