Yes, it's been done, several guys on the board tow gooseneck trailers.
MJW and myself are two. Aluminum vs. Steel not so significant as is the weight. You could theoretically get a 3500lbs steel gooseneck and a 7000 aluminum gooseneck. Steel goosenecks tend to be older and very pin heavy. That's bad. But if you find an older steel 2 horse gooseneck, that's probably not too heavy.
Plan on airbags.