I'm glad this thread was started. My class in college all took the test, which was administered professionally. I remember thinking I get it and vaguely remembered something about ESFP. I always looked back thinking that I must have tested ESFP. I decided to dig it out. I've been typing myself as EnfP because I don't feel very N, it is surprising to me.
When I started looking into it this year I took a test online and then researched it.