I don't think you mentioned how tall you are?
If we're around the same height, it's also possible for proportions to be different... you may have a longer trunk and shorter legs, for instance, than I do, yet be the same height. Looking at how the backplate is laying on your back, it looks pretty similar to mine.
As long as the ab/cod is truly as high as it can get (and while you don't want to sing soprano, you SHOULD be making contact and have it snug... think cup/jockstrap snug, as far as the twig and berries are concerned), you do have one remaining last-ditch option: Split the cod from the ab plate. Then you get an extra inch (or three) of height, and move everything up, which brings the kidney plate up with it. There's a limit to what you can do which this, since that bring the buttplate higher, too, and you can't have that digging into your crack, either, but it can probably at least get you an extra inch without a problem. You can shim the connection between the ab and cod, just like any other shim, or some people even leave it flexible (which actually makes sitting and peeing possible!). The new seam between the cod and ab plate is hidden behind the belt, so this is a permissible mod, for taller troopers.
All that said, cutting the cod is definitely a last-resort situation.