No you are quite correct.
Alex has plans that are very easy to make, link below
Dear Group, on a off-set type still such as the moonshine-still one
> i've seen mentioned before the plans call for 2 valves on the end cap.
> One is for reflux back to the tower and the other for the offtake.
> Would you not be able to regulate the reflux rate just the same if you
> had an equal tee on the end of the cap with a valve on the collection
> side of it. If that valve was closed you'd have 100% reflux and is it
> was opened the rate would drop as the collection rate increased.
> Or am i missing something?
> Many Thanks