One of the first pages I wrote for this site was a request for developers to design a replacement for the Sega Master System 3D glasses adapter that can be installed into a Genesis or SMS2: http://retrorgb.com/genesis3d.html
Well, six years later, someone on the circuitboard.de forums seems to have done it!: https://circuit-board.de/forum/index.php/Thread/26728-TUT-3D-Support-f%C3%BCr-das-Sega-Master-System-II/
At the moment, the installation instructions are for an SMS2, but this should work with Genesis consoles as well. Let’s see who will be the first person to integrate this into a Model 1 Genesis and use the headphone jack for the 3D glasses!!!
The boards can be ordered here: