Robit = Robust Probit
So essentially replacing the normal errors with a fatter tail like student’s distribution. I think you should be able to accomplish with a hierarchical latent variable probit model? Just getting my feet wet so I won’t try to share my bad code, just the GLM Hierarchical example:
https://docs.pymc.io/en/v3/pymc-examples/examples/generalized_linear_models/GLM-hierarchical.html#Hierarchical-Model