Hola Jeffrey 

Sorry to hear you feel frustrated. Kwiziq lessons that are about conjugation of a specific tense don't expand on usage as they are meant to focus on that precise conjugation. Nevertheless we do link lessons so students can navegate and expand on something of that specific content. We have a link inside that conjugation lesson that takes you to a brief explanation on when the tense is generally used and gives you a list of related lessons at the bottom. 

Here is the link included in that lesson in case you missed it. 

We will go back to the lesson to see if we can make this connection more obvious. We will also revise our conjugation lesson for the Pluperfect subjunctive.

Saludos cordiales 

Inma