How to convert all metadata keys from YAML block in the output, not just title, when using -s?

[khaalidrafi]

How to get all the metadata from source file into the output file?

[jgm]

Use a custom template that does what you want with the metadata fields you want to use.

[khaalidrafi]

According to Pandoc manual, custom templates require maintenance:

If you use custom templates, you may need to revise them as pandoc
changes. We recommend tracking the changes in the default templates, and
modifying your custom templates accordingly. An easy way to do this is to
fork the pandoc-templates repository and merge in changes after each pan‐
doc release.

I wish there were some simple command flag so that Pandoc doesn't ignore any metadata from the YAML. Are you interested?