Currently, reading the top-sites configuration from the Remote settings collection is rather hard and as we're moving forward and the collection rules grow in size, additions and substractions to the top-sites collections will become increasingly hard to review, overview and test.

An idea would be to update https://github.com/mozilla/searchengine-devtools to be a place holder for a at-a-glance view of the available topsites for a selected region/locale combination.