When you go to take the ribs out of the foil they will about fall apart during the last hour they will firm back up some if you want to baste them with a bbq sauce the last 30-45 minutes would be the time to do that. Many sauces are high in sugar content and tend to burn easily o adding it the last 30-45 minutes reduces the time for them to burn. Usually my numbers are more like 2-1.5-.1 and I normally don't sauce instead I serve it warmed on the sideWhat's the reason for the last hour unwrapped? Do you put anything on them?