This Module is currently available.
Three Channel Expander for Takaab MIX
Adds three extra channels to the Takaab MIX v2 or Takaab 2MIX.
Connections: Use a 2.54mm 2-pin jumper cable to connect to one of the three pin pairs on the MIX. Make sure to connect GND to GND (top row of pins) and SIG to SIG (bottom row); the cable should not twist. You can connect up to three MIX-Xs to one MIX this way.
https://www.siammodular.com/takaab-mix-x-three-channel-expander-takaab-mix