Wish: command option "chamfer variable radius"

Hello. I ask: “why the command” bevel variable radius “is not referred to the possibility of carrying out the chamfer with a linear and not only of the curved type?”.
(to understand, if I select an edge, and add, for example, handle 4 of different sizes, the chamfer through such points only occurs through a conical, if not mistaken).
Eventually, it would make sense to perform a chamfer with a linear trend? If yes, it has been implemented in 6 Rhino?
Thank you.

i would also like to determine different lenghts to chamfer edge command. not (10,10) or not (20,20) but something like (5,30).

also there is not a looking good solution for attached model. some times i need good looking chamfers,they do not need to be mathematically correct.

chamferedge.3dm (179.8 KB)