Edge weight of 0 should not chamfer when in chamfer by weight mode. Currently it makes a chamfer at 0 scale which ads vertices that cause problems with the mesh. Radius bias would also work better if extra verts were not created.
Also in editable poly the default weight of edges should be 0. Alternatively, an option to set new edges to a certain weight would also work. This way you don’t constantly have to set new edges to 0. The idea is that edges are not chamfered unless there are specifically told to do so.
This system makes for a nice nondestructive chamfer workflow.