I would definitely be in favor of adding Billings to the roster. It would allow the Cowboy to use a day 3 pick on another position than DT.
Some edited notes from Wiki...
As a top defensive tackle prospect, Billings received an invitation to the NFL combine. He attended the combine and completed all of the required combine drills. Fox Sports listed him as one of their top five biggest winners from the combine and his performance was perceived well overall by scouts for his display of brute strength coupled with exceptional quickness and speed for a man of his size. On March 16, 2016, Billings participated at Baylor's Pro Day.
Billings performed well and chose to run the 40-yard dash (4.96), 20-yard dash (2.89), 10-yard dash (1.76), short shuttle (4.78), and three-cone drill (7.74) and decreased his times from the combine in all of them. At the conclusion of the pre-draft process, Billings was projected to be a late-first or second round pick. He was ranked the third best defensive tackle prospect in the draft by ESPN, the sixth best defensive tackle by NFLDraftScout.com and NFL analyst Mike Mayock, and was ranked the seventh best defensive lineman by Sports Illustrated. He drew major interest and was linked to the Green Bay Packers, Washington Commanders, Pittsburgh Steelers, and Minnesota Vikings.
The Cincinnati Bengals selected Billings in the fourth round (122nd overall) of the 2016 NFL Draft. He was the 16th defensive tackle selected in 2016. His fall in the draft was greatly unexpected as no teams gave any indications of it prior to the draft. He was projected as a first rounder in multiple mock drafts by Pro Football Focus and NFL analysts Todd McShay and Mel Kiper Jr. There were many speculations that ranged from his lack of height and size for his position and a possible knee injury. Bengals' head coach Marvin Lewis said “I think his height maybe was restrictive in some ways for some people at times but we’ve done pretty well these guys.”. Billings stated in regards to his fall in the draft, "This is something I'm going to carry with me my whole life," Billings said. "It's actually a good thing for me." He drew comparisons, by multiple media outlets, to teammate Geno Atkins and his equally unexpected slide in the draft during the 2010 NFL Draft.