Whether PYNQ's file system can add a package manager for rpm or dnf supported by petalinux

I want to only use PYNQ file system, do not need overlay function, and want to install rpm or dnf package manager in it, which is supported in petalinux, I don’t know if this is OK.
In addition, I have a question, why in which sdbuild folder in the Makefile file, I see the related petalinux rootfs configuration items, I want to know, these configuration packages or libraries, will also be configured into the generated PYNQ file system? Because after I configured it, I didn’t see my own added library. It makes me wonder.