Bangle.js 2 issues/questions

Just some notes on some of your points:

• Charger shorting out on metal surfaces is a valid point, but more for the attached power source than the watch itself. There are some 3D printable or laser-cutable charging cradles. Those should help out with this.
  
• The bottom "plastic" surface is glass and had a protector on it on my bangles :) The Bangle itself stands up to surprising amounts of abuse for me without looking to scuffed, scratches all over should not be normal on a new one.
  
• Battery charge level is measured as a voltage and not all Bangles are created equal in that respect. There are manufacturing differences in the voltage divider resistors which can cause inconsistent behavior between two watches on charge level readouts. Settings->Utilities->Calibrate Battery on a fully charged Bangle should help with that by storing an offset for the fully charged voltage and essentially marking that as 100%. There is a "Power Manager" app, which can automate this and additionally force monotonic voltage and percentage outputs.
  
• If you have the wake on twist enabled maybe the thresholds can help with the watch lighting up. There are some apps that can cause lighting up sometimes, Quiet Mode Scheduler comes to mind
  
• Normal Gadgetbridge should work fine for the most part, but not all features are implemented there. Bangle Gadgetbridge is not really a fork, just a different build of the same code with more access rights enabled (Internet access mainly). There is an FDroid repository containing a nightly build for the newest features.
  
• Backlight turns on with notifications for me
  
• Sleep stats are not yet transmitted as far as I know
  
• I too have syntax-error toasts, but those could easily be caused by one of my many installed apps, since the do not seem to create any further problem I currently ignore them :)
  
  

The GrapheneOS thing interests me, I see the same problem with another watch and phone and default GB build from FDroid without a solution so far. Does it actually work for you if the APK from FDroid is installed manually by e.g. file explorer or do you mean something like Aurora installing the Playstore-APK by "other client" ?