Question 1: From RLlib’s perspective, there is no difference. We (the Ray libraries) are consolidating top level APIs and, in the long run, would like to match the common “.fit()” syntax you see in many ML tools.
Question 2: They have not changed their place in the config_dict. But the way you construct a config_dict is now with the config objects. This is still being updated in our examples and many other places. Have a look at the currentRLlib in 60 seconds example -