Is it really impossible to order official carrier board apart?

I am one of people who made a silly mistake to order the very first batch of the board alone.
I bought the developer kit again, but prefer to make the sleeping board alive too (in official devkit not partner product…).

Is there any way to order the carrier board apart?

Sorry, no. :(

You may have a look at the Jetson Partner Hardware Products - there are some carrier boards for Nano/Xavier-NX. But they might be a bit pricey as most of them are designed for professional use cases.

Probably cheapest solution is buying a Jetson Nano Developer Kit and use the NX module in there (make sure to get the latest revision as only that support the Xavier NX module). But this will leave you with an orphaned Nano module…