Music as distributed over the 8 figures of the dance:
La Cuisse published his contredanse folios in the mid-1760s, the French style became popular in Vienna in the early 1770s at the latest, and Bülow's manuscript compilation was made in the early 1780s -- therefore it is reasonable to assume that we are speaking about closely related practices. By Schubert's time, things had changed -- the menuet was often reduced to a comical Grossvater dance, and the formal quadrille had by and large been superseded by the decidedly less formal cotillon, or else adopted the latter's tendency to mix dancing with party games. More than ever, the design of a dance was in the hands of the caller or lead dancer (Vortanzer), and the music was shaped accordingly (and sometimes on the spot). As Schubert was playing for cotillons, then, he would take his cues from the Vortanzer (from the reminiscences, this was usually Josef von Spaun).
In this environment, the reprise was the principal device available for an aural structuring of the dance to complement the sequence of dance figures; the refrain, on the other hand, was a way of extending and enriching a particular sequence. The refrain and musical coda are obviously closely related -- the only real difference being that the coda usually consists of stereotypical cadence gestures mixed with material from the preceding sections , where the refrain is substantially new material. It's entirely possible that the refrain was not danced -- along the lines of the published waltzes of the 1830s and later, an instrumental introduction was likely (whether a prelude in the old manner, a vamp to establish rhythm, or a more elaborate piece) and -- if the Vortanzer directed it -- a final strain not danced was possible. One can, for example, easily imagine the dancers standing and clapping in rhythm to the yodeling refrain of D734n11.
The comments above can be regarded as an addendum to the post on performance designs.