I am not sure how to even begin to answer your question, TBT, but me personally, the only time I astral walk is when I sleep. I don't even know if I can lucid dream, or if I ever have. But again, for me personally, astral walking only happens when I am in an extremely deep sleep, which is literally almost every night.
In another of my posts on this astral topic, I stated that there are 4 levels of sleep. REM stage (or dreaming) is level 1 and level 4 (I refer to this as "semi-comatose") is the deepest sleep that one can be in without having to have machines breathing for them. Most people go through the levels of sleep in sequence and in 60-90 minute increments and then the same in reverse. I am one of the oddballs that go from level 1 straight into level 4, and I reach this deepest level of sleep ALMOST every night. I could make my bed and tuck the sheets tightly under the mattress (like they do at hotels) right before I go to bed , and 9 out of 10 times, I will wake up in the same position I laid down in with little or zero disturbance to my sheets.
I hope that I am phrasing this correctly when I say that every astral trip is a "dream" but not every dream is an astral trip.
I don't know how much or how little this helps, but I hope that you find the answer that you are looking for.