I too prefer 80/20 chuck for making burgers. I like to simply S&P both sides of my patties after I get them formed cover them and let them sit out on the counter. In the mean time I get the fire roaring hot. I put the burgers on and sear each side real good. Then I choke the fire down to about 300 offset cook until desired internal temp.
Once or twice a year I like to make a Chorizo stuffed burger.
Fry up the Chorizo sausage (the sausage is greasy so spoon out as much grease as you can) let the sausage cool.
When forming the burger patty make them half as thick as usual.
I place a slice of pepper jack cheese on one of the patties then I spoon on some of the cooled chorizo sausage followed by another burger patty.
salt and pepper both sides of the now formed burgers, and grill them as above.
Oh and some times I add a few mesquite wood chips to the fire for a smoky flavor.