Recording multichannel audio from Roland octa capture

I have a roland octa-capture usb device. I want to capture the audio from its 8 inputs.

I checked lsusb, and got

Bus 002 Device 019: ID 0582:0120 Roland Corp.

Next, I went into alsamixer, and switched the device to OCTA-CAPTURE, and it says “This sound device does not have any audio controls”, which is not a good sign.

Next, I opened up audacity, and I can see OCTA-CAPTURE as one of the possible recording options. The options I have are

OCTA-CAPTURE: USB Audio (hw:2,0): Front Mic 0
OCTA-CAPTURE: USB Audio (hw:2,0): Rear Mic 0
OCTA-CAPTURE: USB Audio (hw:2,0): Line 0
OCTA-CAPTURE: USB Audio (hw:2,0): Front Mic 1
OCTA-CAPTURE: USB Audio (hw:2,0): Rear Mic 1
OCTA-CAPTURE: USB Audio (hw:2,0): Line 1

I see 6 things while there should be 8. Also I don’t know what the mapping from the ports on the hardware to the labels in Audacity are.

Anyway, I chose one of the options and then proceeded to connect a mic to all 8 input ports, but all i get in white noise.

Any help at all would be appreciated.

Roland say that Linux is not supported.
Reports from Linux users that I’ve been able to find from searching the Internet all say that the Roland OCTA-CAPTURE USB does not work on Linux.
I did find one old message where someone said they were able to use it by running Windows XP in Virtualbox - they gave no details, and running audio capture in a virtual machine is far from ideal, but if you have an old copy of XP kicking around, it may be worth trying that.