Glad to read that, thanks for the update! That was the main goal: simplify.
We did not have any "failed" shutdown while development and that means hundreds of attempts. You already have the 5V and the 12V leds in the MacArthur. If these leds are hidden by a casing or some panels, you can add a LED + resistor to the 3.3V/GND pins. when the shutdown sequence is complete, it will turn off. You can also use 5V/GND pins or even the 1W connector, see 1W alternative uses in the manual.
Just in case, calibration should not be "locked". The system should be always re-calibrating.
We did not have any "failed" shutdown while development and that means hundreds of attempts. You already have the 5V and the 12V leds in the MacArthur. If these leds are hidden by a casing or some panels, you can add a LED + resistor to the 3.3V/GND pins. when the shutdown sequence is complete, it will turn off. You can also use 5V/GND pins or even the 1W connector, see 1W alternative uses in the manual.
Just in case, calibration should not be "locked". The system should be always re-calibrating.