Whittler, the Handy Clicker is not a draw check, so it does not, on it's own, set your draw length. However, the added shot control and time at full draw provided by the HC, allows you to develop a solid, consistent anchor to achieve a very repeatable draw length.
The rules are unclear about where the HC would be legal in competition.
Under IBO, traditional bow rules it seems the HC would be legal in the Recurve Un-aided class, as that class permits clickers/draw checks. It might also be legal in the Recurve Class. Recurve does not permit draw checks, but because the HC is not a draw check, it might be considered legal.