I think they just weren’t perceived very well by a lot of folks, people thinking they were a little toy like and instantly dismissing them. People seem to be always pining for a Nuage Jnr and want something with more channels in a single unit and physical faders.
I’ve got the 6 pack plus an additional 3 FD units for 16 faders and think they are great.
I hope you’ve found the additional units you were looking for.