We will note in the description of enableWhen that it's not permitted to have a reference to a question such that the reference could refer to more than one item (e.g. an item within a repeating group).  Will also clarify that if we're dealing with a single item that permits multiple answers (i.e. a question item with repeats=true), that the condition is satisfied if any of the answer values match the enableWhen value. That documentation will indicate that the enableWhenExpression extension should be used in these cases to allow the author to differentiate whether the rule should be triggered based on the value of the first repetition, all answers having the specified value, any answers having the specified value, etc.