I’m not sure about fudge, but the Ankarsrum manual does suggest that you can use it for marshmallows and…”. NOTE: The beater bowl is heat safe and boiling sugar can be poured into it.”
I would reach out to http://www.ankarsrumoriginalusa.com with this question and see what is possible for fudge. Great question, I hope you can. My grandma made fudge until nearly 100 years of age and I marveled at the strength of her arm.