Depending on how many burgers I'm planning to cook I'll usually have at least one small area with no coals, sometimes a slightly larger area. I'll do direct until I think they're done and then move to the indirect area until the rest have finished. I generally use a very hot fire so they cook quite fast. If I'm doing more than six it will often take me long enough to get them all on the grill that the first ones are almost ready to flip by the time I get the last ones on. Same thing after the flip, particularly with the time needed to add the cheese. So they usually spend just enough time indirect for me to deal with the rest of them or for the cheese to mostly melt.