CGMs, all brands like to stay in the same place under the skin and need good interstitial fluid exchange/movement. Therefore, a site in the stomach may have issues because the skin flexes so much that the sensor wire will move up and down in the shin, causing failure or inaccurate readings. If there is pressure on the sensor, such as sitting on it or sleeping on it, the exchange of sugar between the blood and interstitial fluid will slow down and the reading will be low and calibration issues may arise.
The best place for a sensor is an area where the wire and sensor end remain fixed. For me the outside or back of the arm work great. Also, I understand that the there is not need to rotate the sensor place because it is not creating scar tissue like a infusion site. All it does is create a small hole that will easily heal. The only thing you need to be careful of is putting it in the same hole the old one made.
I just listed to an MD from UCSF, who is an expert in CGMs, state that most people have a spot that works best and the trick is to find it and use it.
Hope this helps. Good luck.