From the rule change slide for pop-up kicks from the NFHS, they provided a pretty clear picture of what the rules committee wanted to outlaw. The diagram shows the first "bounce" taking place in the immediate vicinity of the tee, and the ball bouncing high into the air. While the rule doesn't say that specifically, their depiction makes it clear. Now how high is high? That's up to interpretation, but head height (~6 feet) should be an absolute minimum. Maybe the minimum should be higher than head height. The diagram shows the bounce height around 12 feet (estimated). Regardless, the pictures, along with the rule itself, gives us something to work with. If we see something similar to what they've depicted (one bounce in the immediate vicinity of the tee, high in the air), it's a flag.
It doesn't seem like the NFHS is going to give us a specific height or more specific requirements, we just have to create our own cues based on what they already gave us. I wouldn't worry about the kicker. It's going to be happening too fast to try and worry about comparing heights. Personally, I think the best key to go off of is the wings having to look up to see the ball. If they have to look up, the receiver is doing the same, putting himself in a vulnerable position which is what the rules committee is trying to eliminate. This is a cue Sumstine is offering his officials, so it may have been suggested by the committee or at the interpreters meeting.