Claus,
The D-ring should sit somewhere between the midline of the body and the backplate. Your D-ring is too far forward. But, since your high pressure hose looks a little long you should also tie your bolt snap to your SPG rather than the hose. Tie it right next to the gauge itself.
In a pinch, you can also see if you can make adjustments at the first stage such as changing the angle of routing. Be careful not to do anything silly, but sometimes a slight angle could take up a half inch to an inch of hose slack.
In a perfect world having a hose length that corresponds to your preferred hose routing and one that won't let the gauge fall below your body line is the way to go. In the real world if you find yourself making a dive with a hose in the position of your photos it's not a problem in open water diving. In an overhead, you can tuck the SPG under your plate to keep the gauge from scraping a cave or becoming an anchor in a wreck. Or, you can clip it to your left chest D-ring temporarily while swimming through tight places.
If you need to replace the hose you are using with a better length, keep your old hose as a back-up in your save a dive kit since it is manageable.