OnTopic Editor 5.2.0 is a very minor update, which doesn't introduce any new public-facing features, but does make a number of performance improvements, such as reducing the amount of mapping that needs to be performed for each topic by relying on the new lightweight PermittedContentType view model (#50) and supporting the new AttributeDictionary constructor for view models (#49). In addition, it also includes a number of internal code improvements, such as adoption of new C# 10 capabilities (#52), including global using directives (#53).
For a full list of improvements and code changes, see Pull Request #57.