Use of multiple burners for small amount of food

Bear with me on this dumb question. I have recently graduated to a Spirit-SP310 from many years of Q's or kettles. The issue is managing the burners for a small amount of high-heat food. It says to preheat the grill with all the burners on high to 550 or so. Got it. But if I only have one burner worth of food, do I then shut the other two off? Obvious answer would seem to be yes, but that's going to drop the interior grill temperature quite a bit when I need a third of it to be really hot. Is this the right way to do it? Thanks

I'm new the the world of gas (other than my own) so, this is a sensible question and I'm going to be watching this a bit.
And then the question can be expanded to when using three burners for preheat and shutting down the center for "indirect" roasting of a chicken? Fire three, cut center out after ten minutes, five?
I'm going to try that method this evening, like I say, this is the first time I've done this. If it fails, I will have learned something at least.

I regularly cut down on number of burners in use (especially in my Wolf) which is so huge I can almost put my Summit inside of it. But even on the Summit I do this. Though I never cut down to only one burner. On the Summit I always use minimum of 2 (either 1 & 2 or 1 & 3) on the Wolf (6 total) I always use minimum of 3 burners. IOW I like to keep the number of burners in use at no less than 50%. On a 3 burner like yours that's kind of hard but on my own Genesis I always use 2 minimum. The configuration on all of the grills depends on what I am cooking BTW.
I looked at maybe getting daughter and son in law one of the Spirits for wedding gift just could not see all that $$$ for the product. $$$$'s were WAY out of proportion to value IMO. I'm either going to find an older grill and restore it or get something from Onward like a Broil King or Huntington which I feel are WAY better than the Spirit line and as good or better than current and new Genesis lines.

Well, weather was brutal for a first run at a gasser but, I had to give it a shot!
So, with air temperature hovering about 13 degrees, a slight snowfall and a patio heater blazing full on, I fired the first chicken on "Gainsborough". Went with a full preheat all three burners full open then dropped number two out leaving the back on high and the front on about medium. It turned out fairly well, i will need some more practice to become proficient but, it was good.

I have frequently used one or two burners (of my three total) for different cooks. If I have two chickens to cook indirect, I will use the center burner as heat source and put chickens on either side.
Ray