yes of course. I made it today. you need to do some change in universal control.
when first time I connected these two, and plug a mic in my second 1824, all 8 adat channels in UC mixer get the same signal for the mic.
there will be 8 adat tracks in the second 1824 's mixer in UC ,and on the right side of the mixer there will be some tracks name such as mixer7/8 , adat1/2.
these means stereo track (or aux input) and you need to choose the right channel and pan them as a stereo part.
you need to connect the second 1824 usb to your computer and do these on the second 1824 's UC mixer.
for example , when you press adat 1/2, you need to choose adat 1 ,pan it left ,and choose adat 2 ,pan it right and so on. and leave all other channel to -int volume
I think those are aux input. so you need to set the propose channel for them . once you have finish ,then connect the main 1824 and they will work.