I looked in the studio interface, and "graded" is not an available setting for capa "components", because I think the "graded" value is inherited from the sequential (not the vertical, I was wrong before).  So, I don't think it should be its own settable attribute here either.

I think unifying with "Scored" gives us the right behavior, referencing capa behavior.  If the LTI component has a numerical grade, it gets added to the grade of the sequential, which mimics the behavior of capa components.  If the LTI doesn't have a numerical grade, that doesn't get added, which is also the behavior of capa.