Is the source code for the demo at https://demo.payloadcms.com available to browse through?
I'm specifically interested in the SEO field.
We are planning to make the demo repo public after a little code cleanup.
You can use this SEO plugin https://github.com/payloadcms/payload-plugin-seo. I believe the demo SEO fields are based on this.
Let us know if you need anything else.
Awesome! Looking forward to it.