Martin,
The driver itself won't help you since the old user space tools don't know the io box. You wouldn't be able to upload the firmware, adjust the mixer levels etc. (unless you patch the old user space tools, of course).
I'm sorry, I'm a bit confused here. You said above that "You have IO, you can adjust the input levels, switch standby and disconnect the box. So everything works as you would expect it."
With the hdsp*-tools that are currently part of the alsa-tools suite, you cannot control the RPM. Neither can you control a lot of the other RME cards. That's going to change with a whole new set of userspace tools.
So, if you are curious, I can give you the new driver and a small command line program that enables the RPM io box (which is on bypass mode by default). Or you wait until I finished the new user space tools..
Flo