It seems like there was an issue retrieving the details of the Pull Request you are referring to, as no specific information is provided. To give you a summary for an advanced developer, I would need details such as:

• The title and description of the Pull Request
• The changes proposed (new features, bug fixes, etc.)
• The files changed and any significant lines of code
• Any tests added or modified
• Related issues or discussions
• Rationale behind the changes
• Impact on the existing codebase
• Any migration or deployment instructions

If you provide these details, I can assist you in crafting a suitable summary. Otherwise, I suggest checking the Pull Request directly on the Thanos GitHub repository for the necessary information.