After doing some investigation, the BrailleSense 7 definitely seems more secure than the SensePlayer, or the Orbit Speak and Player. There is no built-in root access like Magisk, SELinux is set to enforcing, and the boot loader is locked. Also, the password you set actually uses the real Android encryption and screen lock, meaning your data is actually encrypted securely when the device is powered off; its not just security by obscurity on top that Selvas wrote, like passwords on some of the old notetakers were. Also, it seems very possible to write apps that speak and Braille directly, and receive raw key combinations, and to get the Android screen reader to ignore them; its a lot easier than on the Orbit devices actually, since I don't have to write my own launcher or patch their screen reader. However, you would have to write your own UI framework, since things like widgets and dialogs are not in the AIDL interfaces but in proprietary code that cannot be distributed. It even seems pretty easy to get alternative screen readers like Backtalk or Sandfly working, with the Braille display interface I added initially for the Orbit devices.