And don't forget there is a ballroom dance using an 1/8 turn between the preceeding step and 1 all the time: Viennese Waltz.
For my medal (not competition) dancers I teach: Slow Waltz, Slowfox, Quickstep step 1 straight, Tango with its own CBMP-technique and V. Waltz as above.
With straight I mean that the foot doing step 1 must not leave the track the foot of the preceeding step was pointing to at the end of the step.