Robots.txt and Sitemap.xml

Hello TYPO3 community!

I have a quick question about optimizing the robots.txt and sitemap.xml.

Firstly, do we have a gold standard for TYPO3?

For example, regarding robots.txt, I have the following setup:

User-agent: *
Disallow: /typo3/
Disallow: /typo3_src/

Would that be enough? What about the fileadmin directory? Should I also block search engine crawlers from crawling it?

I noticed that the sitemap is very simple for each language. Google recommends using hreflang to indicate the other language versions in a single sitemap instead of using multiple sitemaps.

What would be the recommended approach for TYPO3?