Sure I am concerned and am pretty well-versed in advanced cryptology myself and protocol/stack weaknesses/exploits. Frankly, Android lost me when I once bought

Sure I am concerned and am pretty well-versed in advanced cryptology myself and protocol/stack weaknesses/exploits. Frankly, Android lost me when I once bought a new phone and after installing a few apps from play store it was spamming me like crazy and discussing stuff with servers in China. Since then I use all Android devices for harmless stuff like browsing while in bath/sauna, controlling my DJI drone, navigation device on my bike, watching edX/Udacity/Coursera/Udemy etc. but never for serious stuff. For serious stuff I use Sailfish on a recent Jolla phone instead with customized security stack compiled from sources (security by obscurity as well).