Do you need this MRCC accessory?

[oldgearguy]

The get the extention part, my question is specifically how 2 MRCC’s connect via USB host.
I see that as sort of cascaded units, use one one USB midi pipe to reach the upstream unit.
Downstream there a 4 USB parts avail.

Two MRCCs connect together via the RJ45 port on the right side of the unit.  The PC USB ports are still free to connect 0, 1, or both of them to a computer.

When two MRCCs are connected via the RJ45, you can have a source device on MRCC-1 and select a destination on either MRCC-1 (as normal) or MRCC-2.  None of that uses the PC USB connections and if your source and destinations are DIN/TRS, no USB is used at all.

If the 2 MRCCs are connected this way and you plug one PC USB port into your computer, the computer will see the 12 virtual ports and you can still route to/from the computer to both MRCCs.  The signal flow might be something like this:  DAW MIDI out -> virtual port #1 on MRCC-1, MRCC-1 PC #1 send to destination #7 on MRCC-2.

The Remote 7 box plugs into the RJ45 jack as well.  You need to make/buy a special RJ45 splitter and then you can connect both MRCCs and the Remote 7.  That gives you 6 DIN/TRS inputs and 17 DIN/TRS Outputs on that MRCC.  If you only have one MRCC, you don't need the splitter - just plug the Remote 7 directly into the RJ45 jack.

The future box (I'm just calling it the 4x1 input) gives you 4 DIN/TRS input ports and it connects to the MRCC via one of the existing USB ports.  So instead of an MRCC having 6 DIN/TRS inputs, 12 DIN/TRS outputs, and 4 USB In/Out ports you now have 10 DIN/TRS inputs, 12 DIN/TRS outputs and 3 USB In/Out ports.