I took one workshop where this was done (attempted) and it was very interesting. The trick is to be prepared to use it/implement it when it's appropriate rather than arbitrarily. It needs to become one of your tango "reflexes."
Indeed.
At the school where I started my journey, the "level system" used 15-week sessions, leaving a seven-week period each year – during the summer's hottest period – that wasn't long enough to complete a level. Setting aside one failed attempt to compress levels into half the usual time (a terrible idea . . . lots of hot, tired, cranky people), they let teachers offer any workshops they liked, be they one-offs or mini-sessions of two to seven weeks. As the go-to accompanier living 10 minutes away, I got called in for
a lot of these.
One was all about ocho variations. That was it, for four 90-minute sessions. Six hours of ochos: regular and overturned; static and moving, both linearly and circularly; pivoting and "milonguero" (crossing); in half and double time; with reversals, rebotes, and pauses; and even ochos locos, which aren't truly ochos. Followers learned to dance all of that. Leaders learned a pile of different ways to lead and accompany it all . . . classic sidestepping, curved sidestepping, contramovement, static lower body with strict torso lead, mirror ochos, opposed ochos, con sacada, etc. As the teacher said, "You could dance all tango with just ochos for the rest of your life and never run out of options."
Another was all about molinete variations. That was it, for four 90-minute sessions. Six hours of molinete: the usual front-side-back-side (FSBS); all the step variants (FFFF, FSFS, BSBS, etc.); changing direction mid-molinete on each step (F, S, and B); changing step variant mid-molinete on each step; changing number of steps to complete 360°; changing pacing from SSQQS; curved vs. linear sidestep; and mutual molinete with all of these variations. Followers learned to dance these things. Leaders learned the tricks to leading them in ways that break the pre-programmed FSBS in SSQQS that most followers do automatically. Leader accompaniments weren't a priority, but we still learned when and where to best use sacadas, enrosques, lapices, etc.
I feel that those sorts of things shouldn't be special workshops, but the standard way movements are taught. Of course they can be broken up across a few levels in schools that have levels.