Most of the time now I use USB sticks to install Mageia i.s.o. DVD.
The installation procedure surely knows where to read during installation, so I would like that it leaves the USB stick as medium in MCC . Now it keeps refering to CDROM, but that is useless.
Most of the time, I change the media to the repositories, but on odd occasions (WiFi not working e.g.) I like to add some more packages before I tackle other things.