Originally Posted by ADDISON
It is great you show the attributes which are not available in some combinations. You made them gray, but do not allow check for them. It is sad to check a box in a filter and see "0 product found". I already know that looking of the color of the attribute. Do not allow checking. You will get a full report for all issue I found in about 10 days. As I read from your post, you continue the work to this module after releasing which is great.
I've registered it as a feature to our internal bug-tracker. Most likely we will add a setting for it disabled by default. There are many popular filters which allow narrowing the list down to zero. Since it's a real-time information it does not cause much confusion.