tl;dr: A way to add a DDR (Dance Dance Revolution ) mechanic to Dancer.
...Valid. How's this then... Let them gain access to the flourishing abilities right at the start. Any 4 button order of these abilities increases combo potency. Display like 4 steps in advance, 4 second input window for the current step. Pause it when using standard or technical step or improvisation. Flat % chance to proc fan dance on the all correct hits, 100% chance to proc on every 8th hit.
Allow people to make and share their own choreographed order of abilities (no simple repetitions allowed). That way they can do synchronization.
And let there be an endless combo counter for the looping sequence of that choreo. Let the proc chance for fan dance scale with different tiers of the combo count. Make it reset if you mess up.
At high tiers of combo, let a free fan dance periodically appear at half steps in the choreo.
Thematically, dancers enter a flow state through constant motion. I think constant motion, constant weaving, would be important.
Also out of pure selfishness, if two dancers pick each other for closed position, let them give each other fan dance procs.
