Yeah. The first rest shouldn't be too long; you don't want to over-do it. The second rest is where most of the conversion takes place so give that time (look at it to see how it's going); 30-60 minutes is typical, I think. I usually do 15-30 minutes at 158 (it's a slower conversion, but it depends on how much body you want). The last one is really just a mashout, so it doesn't matter how long it takes; 10-15 minutes is fine. Long enough for you to be able to start your vorlauf.