I've reviewed security systems from all major brands. Here are my most important recommendations when you're ready to set up your own.

Abstract: In this study, we fabricated a limiting current-type microelectromechanical system (MEMS) sensor and evaluated its sensing performance of oxygen and humidity concentration. The MEMS oxygen ...

Abstract: This paper presents a microfabricated Clark-type sensor which exactly can measure dissolved oxygen in the cell containing solution. We designed and fabricated a microfabircated Clark-type ...

There's no big conspiracy, O2 are simply enabling what is tested and approved at this time. It's no different to VoNR, VoLTE, SA etc. If you'd rather you waited for more devices to be approved, then ...