An iPad will need to connect to the MRCC PC port. So the MRCC will be a device and the iPad the host. I use a USB to lightning dongle with a USB A port and a lightning pass-thru port so I can power the iPad while its connected to MRCC.
MRCC will not work as a USB hub. Since MRCC is the USB host, essentially emulating a PC USB host port, the PC will not see these USB devices. It will only see the MRCC ports, and you can route MIDI data to/from those to the USB devices on the MRCC.
This is a great feature for "DAWless" setups, but has some limitations if you need to control your USB MIDI device with a PC application that looks for the device in the list of attached USB devices. In that case, it might make sense to connect the USB MIDI device to the PC and use some software to route it to the MRCC PC port. Some MIDI tools that might help with that are:
LoopMIDI
LoopBe
MIDI Yoke ( now pretty old-school )
If the application lets you select a MIDI port to communicate to, that should work. You would select a MRCC PC port in the application, then route that port to the MRCC USB host port the device is connected to. That can work in both directions.
Please note, we currently have a limitation where SysEx (and some other messages) is not passed to/from the USB Host ports. We're working to get that added ASAP.
MRCC will not work as a USB hub. Since MRCC is the USB host, essentially emulating a PC USB host port, the PC will not see these USB devices. It will only see the MRCC ports, and you can route MIDI data to/from those to the USB devices on the MRCC.
This is a great feature for "DAWless" setups, but has some limitations if you need to control your USB MIDI device with a PC application that looks for the device in the list of attached USB devices. In that case, it might make sense to connect the USB MIDI device to the PC and use some software to route it to the MRCC PC port. Some MIDI tools that might help with that are:
LoopMIDI
LoopBe
MIDI Yoke ( now pretty old-school )
If the application lets you select a MIDI port to communicate to, that should work. You would select a MRCC PC port in the application, then route that port to the MRCC USB host port the device is connected to. That can work in both directions.
Please note, we currently have a limitation where SysEx (and some other messages) is not passed to/from the USB Host ports. We're working to get that added ASAP.