I haven't heard any negatives on Steele. Not every lineman can be a 1st or 2nd round draft picks. There are plenty of starting formerly undrafted linemen in the NFL today. Seems like almost every team has one.
The Cowboys had one for all three Super Bowls in the 90's, Mark Tuinei. They had an undrafted starter for their first Super Bowl championship in 1971, Center Dave Manders. In the 1977 championship they had a 13th round draft pick starting on the O-line, Herbert Scott.
The guys that make it are the ones that stick, work hard, and improve along the way. Steele earned his starting position on the team. At the very least we know the Cowboys are more concerned with Mcgovern than Steele. Otherwise, they would have Tyler Smith competing at RT instead of LG.