The separation into different block types is because there are far fewer of Type A than of Type B. Thus, the actual test cases could be:

A1-B1
A1-B2
A1-B3
...
A1-B99
A2-B1
...
A2-B999
[download]

So the blocks types form a hierarchy. I hope that makes the problem clearer.

In any case, thanks for the hint about the Config::* modules - I hadn't been aware of them.

loris