This results in an uneven look. To create a more balanced shape, the concave corners have to be filleted at a reduced radius, so that the chamfer brings them up to match the convex corners, while the convex corners will be shrunk to match the reduced radius of the concave corner (pic C).
Here's the cadquery plugin that fillets with this in mind:
use like this:
model.edges('|Z').fillterChamferComp(5, 1).edges('#Z').chamfer(1)
@s_ol very neat!