reiserfs is an excellent filesystem, one of the best for general purpose use. Fast, efficient, rock solid. Ity should be listed as a viable option. Not doing so for political reasons is silly. BTRFS, which is listed is among the worst, perhaps the worst, but it's listed. C'mon, using reiserfs doesn't mean you support murdering your wife, any more than buying a Volkswagen means you support Hitler. Unless someone presents a technical reason why iyt should be excluded, I will add it back in. I have had hundreds of systems running it, and probably 500+ disks formatted with it, never once a problem, but I have rescued many a failed disk using it,.
we should officially support JFS as default since it's high performance, and reliable. funtoo's known for speed and JFS is the highest speed file system out there. root partitions will probably be flash memory, solid state drives, or nvme... they should be omitting swap. we should handle swap by swapfile creation on rotating storage disks elsewhere in the install....
root # mkfs.vfat -F 32 /dev/sdc2 root # mkfs.jfs /dev/sdc3