Is IntelliJ Python 3 inspection "Expected a dictionary, got a dict" a false positive for super with **kwargs?
Yes, that appears to be a false positive.
You asked about formatter_class=kwargs.pop('formatter_class', argparse.RawDescriptionHelpFormatter). Please don't do that. Mutating kwargs, which appears as the next argument, seems Bad. Additionally, default keyword args should be set to a simple constant rather than some mutable datastructure, as there is a big difference between evaluating at import time and evaluating at run time. See e.g. http://www.effbot.org/zone/default-values.htm . The usual idiom would be formatter_class=None in the signature, and then in the body you test for None and you mutate kwargs to your heart's content.
Marking all the virtual environment directories stored inside the project (e.g. ./venv) as excluded has solved it for me with PyCharm 2020.2.3.
To do so: right-click on the virtual environment directories in the project tree and select: Mark Directory as -> Excluded. Solution from https://youtrack.jetbrains.com/issue/PY-39715.