• check if the value of the kwarg is None, at least for kwargs that are used to identify a method. If it's None, it should be discarded.
• Possibly add support for passing objects in their dict-representation, e.g. document={'file_id': '...', .…}.

Combined, that would improve support for doing something like send_by_kwargs(bot, **message.to_dict())

See here for some discussion: https://t.me/pythontelegrambotgroup/565277?thread=565248