This Module is currently available.
quad MIDI DIN expander
nexusMIDI is a midiphy phybus expander that adds classic MIDI inputs and outputs to connected phybus modules like zetaSID. It allows connection of external MIDI keyboards, controllers, and sequencers to control your phybus instruments with two classic MIDI input ports. It also offers two classic MIDI output ports that can be used to transfer MIDI data back to external gear, for example in conjunction with zetaSID it can transmit arpeggiated notes and SysEx patch dumps.
These merchants probably sell this module. Huh?