Trying to emulate the DivIDE on Spin

I have this .iso image that's supposed to be used on a cf card:

ftp://ftp.untergrund.net/users/gasman/zx/divip_let_forever_be.zip

Since I don't have a DivIDE yet, I thought I would use Spin to test it. I chose the +2 model, checked the box for DivIDE emulation, chose Demfir to be used as firmware, but I don't know how to use the .iso. I see the option to mount hdf images, but not iso images. I really want to see this. :(

edit: I extracted the .iso and mounted the .hdf.