I am not expert on Hapkido. Pick the lowest level of Hapkido practitioner and there I am. I don't teach Hapkido either.
I learned some similar stuff before I began Taekwondo, under the jujitsu name in Karate, and Hoshinsul name later in Oh Do Kwan/Moo Duk Kwan/Tang Soo Do. My Sabumnim, GM CHONG Chun Sup added it in his Taekwondo classes from what he had learned in Pyongtaek, Korea. I began training with him after he had been in the USA for only 6 weeks, he did not speak English at the time, I never asked any of these questions because I studied it very little and had very little interest in Hapkido, but years later I played around with it "a little bit" with some of my own students, and through Taekwondo and my many trips to Korea, I have encountered Hapkido from time to time in Mexico, USA, Canada, Europe and even at the "Hanminjok Korea Kido Hae" - if I got the name right - Headquarters in Seoul. I have also attended some day long, and even week long training events.
I think that firmly plants me in the novice category, that is why I ask these questions. But I might decide to take up the study of Hapkido, and if I do, I will find the best possible source and go study with them, or, bring them to the USA where they can stay at my home and study with them everyday, and invite my students to do the same. I've been known to do that kind of thing before.