Everyone's got their own interpretation of how to do ribs... as Ron50 said, the 3-2-1 method is more of a guideline than an absolute.
I watch carefully for the pullback of the meat from the ends of the bone during step "3". If I'm getting 1/4" to 3/8" pullback in less than 3 hours, then I'll go to step "2".
During step "2", I'll leave them in the foil, normally (depending on size) for the full two hours, making sure there is plenty of juice in the foil with them.
Step "1" is an eyeball/gut thing. You want them to firm up a bit during this period. I baste them with a sauce of some kind during this phase, and usually pull them when they "feel right"... this could be less than an hour. Some like to check the internal temp and get it to around 170-175... I usually don't bother, because they really get done in the foil.
Smoker temp during the whole episode is 225-235... Smoke Gods willing...