I don't have aphantasia but I sometimes also have dreams that are so realistic that when I wake up I feel as if it was some type of alternative reality. In some cases it is also as if I am watching a "movie" where the life I am experiencing is not my own, but I will still know each person.

That's fascinating. Do you gain access to facts or knowledge that are verifiable afterwards? Have you ever become fluent in a foreign language for a dream?