Using multiple CI 1 units?

Hi All, sorry if this is old hat for you but I can’t find an answer elsewhere.
I’ve used a CI 1 on mac OSX very happily for two years or so. I’ve a project coming up that will need 4 channels not 2 and I wondered if it is practical to use two CI 1 interfaces simultaneously while recording into say Cubase. Has anyone tried that before and had success or failure? If it’s possible then buying another CI 1 (or more recent equivalent) might be a very cost effective option for me.
Any comments gratefully received!