The Operating System is a very important element of whether the device can be location tracked or not. If your device is not privacy oriented AND has any kind of signal processing receivers (cellular, wifi, bluetooth), then its impossible to hide its location because the OS can access those elements directly and use them to gather location related information and then upload them to some server.
So you have to make sure the OS of your system either doesn't do that or doesn't have access to any signal emitting/receiving.
For example it is possible to hide the location of a google based android system that has no cellular, wifi, or bluetooth hardware, by placing it behind a hardware firewall that has vpn running on it.
But if the device has any of those signal processing components then the OS itself HAS to be trustable not to abuse or leak with those components.
So, getting a good OS is critical. But there are very few devices that can host these OSes. So your actual options are very limited.
Also read my response in your other post. https://discuss.grapheneos.org/d/5443-device-recommendation
Also take into consideration whether your needed apps can work without google play components or not. If they require google components, then you need either GOS or a system with Micro-G installed. This depends on your apps' needs. This further limits your OS choices.