Pipe command how to get rounded corners?

Pipe command how do I get rounded corners ?

In a Graphics prog one had the option for rounded bends or harsh bends I recall. The centre line had a line thickness with bend types and end cap types, so no structural wall but the file resulting understood the thicknesses and allowed them to print, …as graphics progs work as such.

Here the cutter will make an impression so what its made of is not so critical, as it then is turned off !

Here I find myself about to enter tricky territory adding radiused circles and trimming so as to dictate the rounded bends. and I foresee fun and games in the area where the upright of the R meets the junction as shown.

Any better methods ?

I intend to half etch boolean difference half the surgace out of a solid.