There are numerous signaling dynamics involved in gastrulation. Using biophysical modelling, we find that liquid-liquid phase separation significantly improves the processing of transcriptional factor β-catenin in the canonical WNT signaling cascade. Using a finite element method, we find that a nucleating region can facilitate a nearly two-fold increase in β-catenin processing. Moving away from microscale biophysical dynamics, we employed a large-scale loss of function drug screen on 2D cultured embryo bodies and found that the 2D system can be used as a powerful, cheap, and reproducible teratogen screening platform and discovered the surprising role of inflammatory and immunological signaling on human gastrulation.