Available as an assembled Module and as a DIY project.
This Module is currently available.
MG ID: 48465
Advanced output module
The Output Bus allows for summing style mixing, external gear integration, soft clip limiting, flexible output types, headphone monitoring and level visualization.
The module can mix other mixers in your setup, return mono or stereo FX into the master bus and bring in external stereo line level gear. You can visualize your final levels, output appropriate signals on the right cable type and monitor in headphones.
These merchants probably sell this module. Huh?