In the quest to get the back of a plane iron flat, is it possible to remove too much in just that small area? Without the rest of the iron being done, soon the iron will be thinner right at the edge, making it not bed properly as the rest of the thicker iron would hold the thinner from any contact with the mouth opening. May be a cause of the mythical chatter one hears about. At least for a bevel up iron.

Also, does anyone flatten the area right behind the bevel? Same as above. If that area is not flat like the back is, how can it mate to the planes bed? You may have a case of a flat back mating to the chipbreaker, but a convex side behind the bevel not allowing the iron to mate to the bed. Or, it may be concave, letting the middle of the iron a space to chatter in? Case of mate to the Chipbreaker, AND the bed of the plane.

Since the only irons I use are the original ones the planes were sold with....including the bevel up block planes. Might be something to look into?