The whole basis of the dance was predicated on the Bolero ( Pierre, freely admits that ).
The bolero in use at that moment in time, was an American version of the " show " type, being performed -by the likes of Veloz and Yolanda .
The content adapted to " 2 " of the bar , instead of "3 ", made a huge impact on its interpretation. The N. Yorker ( crossover break ) was an integral part of the social Bolero being taught at that time . The " checked " actions, were designated as " breaks ", still are ..
In real terms, a checked action can perform 2 functions, a momentary delay on a fwd progression-- or-- a " return " to a preceeding position.
I believe this discussion, is as much about semantics, and little about definition.
To my mind,something " checked " is something " delayed ".
A rocking or breaking action, denotes a fairly prompt return, to the non supporting leg , retained in its same position .