That's more of an Android related issue more than the script. It doesn't matter what image you use but if you set up your android partitions manually you can make it any size you want. You can still do so even if you use the script but that's a whole different matter.
What you have to keep in mind is that after flashing android you have to first boot it to twrp by holding onto vol+ when booting android and then install gapps and whatever else you'd like to add, then reboot to android from twrp when finished.
I never boot straight into android knowing that there's more to setup before intializing android, so unless it's something else that causing it I can't tell you since I never had an issue installing android
What you have to keep in mind is that after flashing android you have to first boot it to twrp by holding onto vol+ when booting android and then install gapps and whatever else you'd like to add, then reboot to android from twrp when finished.
I never boot straight into android knowing that there's more to setup before intializing android, so unless it's something else that causing it I can't tell you since I never had an issue installing android