If so, it is difficult to install individually.
After installing the os and jetpack-component on the emmc module, there is about 1 gigabyte of capacity left, so if you want to install and test other software, you need an auxiliary storage device, right?
I will suggest that perhaps you only need to mount the external storage device in a simple manner, and not boot directly to the external storage. What do you see from these commands?
df -H /
sudo du -h -s /usr/local
Depending on how storage is used it might be a very simple transfer of content in “/usr/local” to the other device, which is quite easy to set up.