Part of the LCO job is to make sure the proper safe distance is observed for each launch. Our circle of pads have 15 feet between each so motors up to D-impulse can be fired on pad n while someone is setting up on pad n+1.
With the number of inexperienced people we had at the previous launch, I generally waited until these folks were done and back behind the flag line before launching. When we had an E-, F- or G-impulse motor, I had to remind many to back away to get the 30-foot clearance required as a minimum.
If you don't mind, I'll take down the other thread you started with the same post.