You can't backup/restore individual components in NSX , it is certainly unsupported. Restore NSX Edges
VMware NSX 6.3.4 - Is it possible to restore a Single NSX Edge / DLR instance rather than doing a complete restore of NSX manager? . However you can certainly take a backup of edge configuration data via API and push to new edges.
Thanks for the comment on this.
We will do the testing with API based backup/restore for Edge. It is not supported though.