Thanks for that article. He has shown enough for sure to give him the rest of the season and try to improve at this level. The article is spot on that he can't just ignore the lower third of the zone. If you can keep the eye level of the hitters honest then that 4 seamer up in the zone becomes more effective.
Folty could legitimately become an ace or an 8th inning guy. The difference between his ceiling and floor is really large and it all stems from his erratic control.