What happened to crossbox?

Unlimited B has only one crossbox maneuver (a humpty where the loop over the top is crossbox), and Unlimited A has two maneuvers, but one is just the entry to a roller. Personally I think the most interesting parts of the more complex advanced/unlimited sequences are the crossbox elements that require planning and skill to position properly. In some sequences it seems like back to back crossbox maneuvers make it go even faster because it makes it impossible to draw a long line between maneuvers. Is this an intentional effort to control sequence size?

Anyone know the story?

-Adam