Hi Anton,
Thanks for your suggestion. I know they’re symbolic links to ttyS0 or ttyAMA0. However, they’re created by the OS itself and determined by whether the miniuart-bt dtoverlay is set. If it’s set, serial0 is ttyAMA0. If not, it’s pointing to ttyS0.
Now, I can imagine you might say “use miniuart-bt on all your devices then”, but because of an issue that happened recently, which took quite some time to debug on our running devices, I’d like to use the serial0 symlink of the OS itself. If the miniuart-bt overlay was overwritten, the application would still function.