The concept has been the same throughout the season, whether it's Inside Zone or Zone Read. The CONCEPT itself, however, is actually quite complex. The lines I drew earlier don't do it justice at all.
Zone blocking needs a ton of repetitions against thousands of fronts. When to deuce bump, when to scoop, when to let go, how to pick up a stunt, a blitz, all of these different factors are relevant in a Zone blocking scheme.
Five guys need to have the same plan for it to work. If Denver is having more success now, it's probably because their line is getting more comfortable with each other.