These devices often run a customized version of LineageOS (like the "Hypocrat" ROM) designed to support the Passport's unique 1:1 aspect ratio and physical keyboard. 2. Software Exploits (The DIY Enthusiast Way)
If your goal is to run Android apps, start with Option 1 (sideloading or Android runtime) or Option 2 (container) to avoid high risk. Only attempt full ROM replacement if a well-maintained Passport-specific Android port exists and you are experienced with device modding.