I have a Nano J1010 with the inbuilt 16GB memory.
I have found that it is virtually useless- by the time you have the standard Jetpack installed, there is no space left for anything else.
(as an aside- I’m in Australia & this device was quite expensive & I had to wait ages for it…)
If I buy a different carrier board https://www.seeedstudio.com/reComputer-J101-v2-Carrier-Board-for-Jetson-Nano-p-5396.html- that has an SD card- will I be able you use the main chip from my current Nano ??(i.e removes the memory constraint)