So you have created a lofted bend that yields a great flat pattern only to find out that there is no bend information associated with it. What happened?
In order to have your bend lines created within SolidWorks for this particular feature, you need to make sure that "each profile includes corresponding curved and straight elements." To clarify this, not only do you need to have the same amount of "breaks" in each sketch creating the lofted bend, but those breaks need to be connected to like items, (radii has a corresponding radii, line has a corresponding line.)
Here is the sketch of the base, or squared portion of our halved square-round:
As you can see, there are 2 radii and 3 straight line segments.
In this first example, the half square round has the appropriate amount of breaks, yet the line types do not match up. This yields a correct flat pattern yet at the same time does not give us bend line information:
(Note: For dimensioning along an arc, check out our other posts!)
Here we have corrected our "round" sketch to contain the appropriate amount of arcs and lines:

Easy as that.