Interesting. So I thought it was just using rpm under the covers but it looks like it's actually using yum to do the deploy (right I know yum uses rpm eventually). You should look at /usr/nsh/patch/linuxpu/Work/linux-deploy.sh. That should be run to do the deploy (it's copied to each target during the deploy and fed a bunch of options).
Btw, in newer Fedora versions I know the 'repackage' option in rpm has been deprecated for a while, so it's likely going to disappear from rhel soon.