Instead of the reverse sear, here is the method I use for ribeyes on the BGE.
Start with a nice thick steak. Ribeyes from Costco seem to be the right thickness and marbling for this method. Seasoned up with Fiesta Uncle Chris' Steak Seasoning.
Lit up the BGE in two places. I remove the chimney entirely and open the damper all the way. We're shooting for 600-700.
Once we get up to temp, put the chimney on and leave the damper wide open. We want high heat without high flame.
Time to put on the steak. Leave the damper open, and close the chimney as much as you need to to stop flare-ups. I CAREFULLY peek down into it to make sure I'm not flaring too much. Exactly two minutes from the meat first hitting the grill, open and quickly rotate 45 degrees.
After another 2 minutes or a little less, flip the steak. You should have nice, even diamonds.
After another, you guessed it, 2 minutes, rotate again 45 degrees. Shut the damper and open the chimney and pull it when it passes the poke test. Oddly enough, about two minutes. Let it rest for 5-10 minutes and should be perfect.
This method has been amazingly consistent. Ribeyes and New Yorks work best, though tenderloin works fairly well too.
Plated up with some roasted taters and a zucchini mushroom bacon hash.