I don't have the magazine, but look at the Evenflo Chase. The harness adjuster is on the chest, just below the chest clip. It does a good job of preventing belly-button clips.
On the chase, there are two harness straps. One is pretty short, and goes from the right shoulder to the harness adjuster (and has half the chest clip threaded on). The other goes from the left shoulder, through half the chest clip, through one buckle, through the shell, under the bum, up the other side of the shell, through the other buckle, and to the harness adjuster. I've played with it in the store, and found that the harness took fussing with to get adjusted properly (had to help the slack through all that routing to get it evened out), and my 25ish pound, 3rd percentile 2yo has almost maxed it out by height. When she was 1 and 20, I could not adjust the harness tight enough (the adjuster was against the crotch buckle, and still too loose), and she was right at the bottom slots at that time. Moving up a slot probably would have used up enough slack, but then what's the point of having the bottom slots?