me neither. But the mlflow documentation suggests the new version of mlflow should be able to handle Array and Objects (dict). maybe that could help? I haven't tired it myself. 

Support for Array and Object types was introduced in MLflow version 2.10.0. These types will not be recognized in previous versions of MLflow. If you are saving a model that uses these signature types, you should ensure that any other environment that attempts to load these models has a version of MLflow installed that is at least 2.10.0.