The current Device handler for the MIMO2+ does have the inputs and outputs unrelated if you set the main device relay operation to manual. But it still only creates two devices.
The problem is the handler works the relays just fine but when the state changes in either of the sensor/inputs it does not register in Hubitat. I have asked Hubitat to look into it and it has been a black hole. I encourage you to try it and see if it works for you. Then you can let me know what I am doing wrong LOL. Within each child device there is a contact and a switch field. I can get the switch (relay) to work but when I cause the sensor (input) to register on the MIMO2+, the contact does not open/close in Hubitat.
Here is one of my prior posts. I think I have another as well:
The good news, and I highly recommend it, is the Zooz Zen16 multi relay with contacts just came out. It works exactly like the FortrezZ MIMO2+ but even has more features such as in the event of a power outage being able to have the relays go back to the last state they were in. Good for a water valve application in a house up in snow country when the power goes out!
Take a look. It is brand new and is being supported, unlike the FortrezZ which I think the company was sold and it is a fairly old part in the Zwave world. Close to the same form factor as well, which is nice if you have limited room and need to swap it out in a prior application. I have bench tested it last week and it works great with the built in device handler. Also has a cool feature of the relays being timed as well. (timed on OR timed off) very cool. But Hubitat forgot to make them configurable with the initial Device Handler. Though they were going to get that working too