Hi. thanks for this awesome extension!

I was very happy to find that it also works with sphinx.ext.napoleon by now :) - learned about this extension via https://stackoverflow.com/a/20845306/10606962 where it said that it didn't support napoleon at the time.
However, I noticed that references are not resolved if you link to a parameter from within the docstring of the function itself, i.e. if you have something like

def foo(arg):
    """:paramref:`arg`.

    Args:
        arg: stuff
    """

TBH I'm not sure, if this specific to napoleon, as I haven't tried with the default docstrings. It is rather easy to work around this, though. Instead of using the built-in PyXRefRole for the paramref role, I used a subclass along the lines

class ParamXRefRole(PyXRefRole):

    def process_link(self, env, refnode, has_explicit_title, title, target):
        title, target = super().process_link(env, refnode, has_explicit_title, title, target)
        try:
            # if we just have :paramref:`arg` and not :paramref:`namespace.arg`, we must assume that
            # the current namespace is meant. Let's extract it from the refnode and prepend it
            if '.' not in target:
                target = f"{refnode.source.rsplit('.', maxsplit=1)[-1]}.{target}"
            return title, target
        except Exception:
            return title, target

For now this does the trick as workaround, but I thought that it could be maybe added to this lib :) By the readme, it's important to you to rely on as few sphinx internals as possible, so I can't judge if this would be acceptable for you. But IISC you use some attributes of nodes already …

Anyway, let me know what you think :) If you like the solution, I could send a PR.