It would provide a better user experience if you didn't have to manually mount the sd card and run the mysetup script.
my suggestion to make this more automated would be to store the ip address of the dev system stored on the sd card and it can be changed there if need be.
the sd card and these scripts can then be run during startup by changing the rootfs that is loaded. this should probably become the default not just an option.
For new and non linux users these steps can be a pain and hard to grasp.
This partially fixed - the SD card is mounted at boot time now.
But the script must still be executed.
The real solution is an easy way to have a script on the SD card that will be run at boot time.
So this is still open.
add step to ensure it is run automatically after it runs correctly.
modify rootfs to run a script automatically IF IT EXISTS.
Then the doc can say to put it there after it works properly.