I want to use pungi to make a custom iso, to put on an usb key, to install some custom fedora system.
And I'm a little lost with pungi

It seems that "old" pungi using python2 will be replaced by a new one called pungi-koji? Or is it a completely different one?
Because previous pungi is now in subpackage pungi-legacy and not anymore in pungi package, but I don't see information saying that pungi-koji is the new tools.
And pungi-koji seems completely different with a configuration file and not using anymore a kickstart configuration file. (documentation here: https://pagure.io/docs/pungi/ ) But is it stable and usable now?

Which tool is actually used to make fedora spin and fedora server (other than live version)?
pungi (legacy) will not be supported anymore?

So, can someone tell more about all this?