(Part II)
Those parts that may be said to be horizontal include asking the intercession of saints (in the Eastern rites it may be the Troparia and Kontakia as well as the requests during the Canon), the Collects, and the Orate Fratres.  In some Eastern rights the Kiss of Peace is non-optional.

There may be others but I'm not going to do a lot of research on this topic; these should suffice.  Regardless, horizontal and vertical are not either / or propositions.  If you disagree, fair enough, but take it up with Pope Emeritus Ratzinger and others who have written more eloquently than I on the topic.