Stratifying random assignment in experiments among demographic quotas would be useful. Right now this is only possible by asking participants their demographics in your survey prior to randomly assigning them to condition. This creates a methodological artifcat in that by doing so, you are causing participants to think specifically about their identity before answering survey questions. Research (see Shih et al., 1999, for example) shows that this type of identity priming can alter responses. If you allowed passthrough data for Connect Demographic Info (e.g., political affiliation, gender), you could use survey flow logic to stratify random assignment without priming the social identity.

Reference: Shih, M., Pittinsky, T. L., & Ambady, N. (1999). Stereotype susceptibility: Identity salience and shifts in quantitative performance. Psychological science, 10(1), 80-83. https://doi.org/10.1111/1467-9280.00111