Comment # 6 on bug 994415 from Franck Bui

Apparently passing multiple consoles to the kernel command line indicates to
the kernel that it should emit its own messages to all consoles but data
written to /dev/console from userspace is only sent to the last configured
console.

According to https://github.com/systemd/systemd/issues/3403#event-755108845,
this is supposed to work on Fedora so I gave it a try and indeed it worked.

After some research, it seems that plymouth is involved in this black magic.
Disabling it makes the status messages to appear only on one console.

Ismail, as you appear to be plymouth maintainer, could you have a look and tell
us if it rings you a bell ?

Thanks.