Yes, I too know exactly what you're talking about! The tags are really inconsistent and don't truly indicate the number of lessons that may cover that grammar point. Some lessons, especially the early lessons, may skip tagging the grammar altogether.
However, there is hope. If you have a Premium subscription (I think), you'll have access to Grammar Bank from the Learning Center, under Reference Material. With the Grammar Bank, you can search for a grammar point and click on the summary page for that grammar point. It'll feature the explanation for the grammar, as well as some example sentences (sometimes, they're the same example sentences from a particular lesson's PDF). Also, I've noticed that you can sometimes find explanations for grammar points that haven't had a lesson dedicated to it yet.
I think that the golden nugget of the grammar bank is that on the summary pages, when you scroll all the way to the bottom, you'll find links to the lessons that have either featured or used that particular grammar point.
Also, here's the grammar page for the combining adjectives:
http://www.japanesepod101.com/learningc ... rammar/360
(There weren't any links to lesson PDFs for this grammar point though
)
Hope that helped!