Hi Derek,
This feedback is probably coming too late because you're probably facilitating the activity right now, but another option could be to slightly lengthen the pairs and foursomes parts of the 1-2-4-All to have the person listen to their partner's top theme and share that person's rationale with the foursome instead of their own:
(1 min) Take a minute to write down your response. (4 min) Share with a partner. Listen and take notes on your partner's important theme or concept and their reason why. (8 min) Join your pair with another pair. Make the rationale to the two new people for why your partner made their choice in the new group of four. (ALL) Defend yours or your partner's choice to the class and discuss.
Just a riff/variation on your idea! Love that you're using Liberating Structures.