Reverse sear....Do you always let it rest first?

I've never done the reverse sear like you do.  Whatever works best for you is the way to go. 

I typically take it to an IT about 5 degrees less than my target then sear it for 1-3 minutes a side just to caramelize the meat.  I just eyeball it at that point.  It takes longer on my gas grill than it does over glowing hot charcoals.   

I do not let it rest before I reverse sear it.  I let it rest afterwards. 

I let it rest before searing. I have a few reasons.
1. I feel like it makes it easier to control and dial in the final internal temp. If the carryover is done before I sear, it's less likely that it'll continue rising in temp after the sear. If it doesn't carry over as far as I'd like, I can always just sear it a little longer until I get the IT I want. If I overshoot, there is no fixing that.

2. Once the meat is rested and the juices are reabsorbed, the sear is only happening at the surface, where I want it. Less chance of the "bullseye" effect.

3. With my mini, it takes about 15-20 minutes once I remove the pot and stir the coals for it to get really raging hot. This turns out to be the perfect rest period for steaks.

I smoke on the WSM then directly to preheated gasser then rest. Usally smoke to 110-120*IT grill 1-3 min per side depending on meat thickness.