It seems that the details of the Pull Request (PR) for the Thanos project were not provided in your request. To create an effective summary, I would need information such as the changes proposed, the motivations behind the PR, any relevant issues it addresses, and how it impacts the project overall.

If you could provide more details or an outline of the key points from the undefined Pull Request, I’d be happy to help you craft a summary tailored for an advanced developer!