Why do you need drives connected to dom0? You should not do anything in dom0, except managing VMs, otherwise you break the security approach of Qubes OS. More info: Device handling security | Qubes OS.
If you are really sure you want to do this, then you could try to take the advantage of the different USB controllers, if your hardware has it. You create a USB qube, add one USB controller to it, and connect to it devices which shouldn’t touch dom0. And use the other USB controller for devices connected to dom0.