Board Thread:General Discussion/@comment-36579093-20190625052621/@comment-1038387-20190625232831

To elaborate n above: people can't lose achievements, unless they're blocked. However, if they change a category from To Do to Done, that is no longer counted as an edit to a page in Category:To Do and it will not count on an edit track on Category:To Do. You could create a track for edits on pages in Category:Done, but it gives the same issue as before: unrelated edits are also rewarded. Custom badges is a really limited feature.