Funtoo mix-ins currently stand at:

X, amazon-ec2, audio, cinnamon, console-extras, dvd, encrypted-root
gfxcard-amdgpu, gfxcard-ancient-ati, gfxcard-intel*, gfxcard-intel-classic
gfxcard-intel-iris, gfxcard-nouveau, gfxcard-nvidia, gfxcard-nvidia-legacy
gfxcard-older-ati, gfxcard-radeon, gfxcard-vmware*, gnome*, gnome-3.16-fixups
hardened, kde, kde-plasma-5, kde-plasma-5-new, lxde, lxqt
mate, media, media-pro, mediadevice-audio-consumer, mediadevice-audio-pro
mediadevice-base, mediadevice-video-consumer, mediadevice-video-pro
mediaformat-audio-common, mediaformat-audio-extra, mediaformat-gfx-common
mediaformat-gfx-extra, mediaformat-video-common, mediaformat-video-extra
no-emul-linux-x86, no-systemd, openvz-host, print, python3-only
selinux, stage1, vmware-guest, wayland, xfce

There are many that arent being used (deprecated) and some that are very obfuscated leading to confusion to some users who might be new to Funtoo. And there is little documentation on what mix-in does what on the Funtoo website.

For instance:

kde, kde-plasma-5, kde-plasma-5-new (this is plain confusing at the very least)

python3-only (this can cause users trouble as we still have python2.7 deps for some things, docs probably needed to explain a use case for this one if it is kept)

gnome-3.16-fixups (way beyond that version (3.36)

no-systemd (as i understand, this was an issue 6 years ago, but seeing that I have never enabled this, I am not sure it is needed anymore. But i could be and have been wrong on such things)

Graphics cards may need some explaining, as we have a few versions for each (like a cut-off point i.e. date and/or model number for the ancient or classic ones)

I am sure there are others that could use some cleaning but these are off the top of my head.

It would simplify things and keep new Funtoo users from making mistakes when setting up their Funtoo system