The file /boot/armbian_first_run.txt is sourced by a bash script (/usr/lib/armbian/armbian-firstrun-config), but only if the file /root/.not_logged_in_yet exists.
On modern disks (modern as in the last 25+ years) the heads don't have to be parked. When you remove the power, the heads are automatically parked. The momentum of the rotating disk is used to provide the energy.