A power status LED can be added to check for safe power off after Pi Zero halt.
Based on the Display GPIO pin usage the following UART GPIO pin is not used by the display and can be used for power status LED.
$ tail /boot/config.txt
enable_uart=1
| PIN | GPIO | TYPE | LED Connection |
|---|---|---|---|
| 6 | GROUND | LED - Cathode shorter lead, 330 Ohms Resistor | |
| 8 | GPIO 14 | UART TX | LED + Anode longer lead |
Alternatively we can also use the power bank status LED for device power status or use a light pipe or TOSLINK S/PDIF cable glued on to the status led on the Pi Zero.