Card sort with student-generated cards

Is there a way to create a card sort activity that also includes cards with content that students have submitted earlier in the activity? I figured if something like that existed, it would be under a sink for the card sort component.

Not currently possible, sorry.

I assume this is still true? I can’t find a way to do this and was just asked about it by a teacher.

Correct, no sinks for card sorts. And the only sources at the moment are for counting the number of correctly grouped cards (generally speaking).