Anyone used conjoint analysis to test sustainable packaging trade-offs?

Yes, conjoint is actually perfect for this exact problem — it forces real trade-offs so you get past the social desirability bias you'd get from a direct survey. We ran a CBC study last year for an FMCG client with attributes like material type, price premium, and recyclability claims, and found consumers would actually pay about 8-12% more, vs the 30%+ they self-reported. Qualtrics or Lighthouse Studio are solid tools to run it.