Example #1
You have a Pline with a width and fillet it with a Line, the line will join the Pline and take on all of the Pline properties including the width.
Example #2
You have a Pline with a width and fillet it with a Pline of a different width, the Pline will join the other Pline, and will take on all of the Pline properties with the exception of the width.
Is there a reason for the behavior where in Example #2 where the Pline has two different widths after being joined? The outcome I am looking for is for the Pline and Pline to act like Example #1 in the end.