I want to install Fedora coreOS on one of my SSD. I would like to use Btrfs filesystem for Fedora coreOS.

1- Is it possible?
2- If yes, what is the way to do it?
I am working from an existing Linux host (archlinux) on which I installed "coreos-installer" via cargo.
I have a device Btrfs formated, with a few subvolumes.
Now, the doc says I need to install on an unmounted device. My plan was to mount subvolumes and then install the OS on the mounted partitions.

Can anyone tells me how to proceed? Maybe use the live ISO installer instead of coreos-installer? Anyway to chroot the mounted device and then install Fedora coreos on it (that would be the simplest)?