Available as an assembled Module and as a DIY project.
This Module is currently available.
MFOS Mixer
Synthcube's Eurorack MFOS Mixer
https://synthcube.com/cart/music-from-outer-space/mfos-eurorack-modules-1569572042/mfoseuro-vco-freq-1125063596
These merchants probably sell this module. Huh?
Included in 61 Racks, 35 are public: