We are about to release the REST API Head Tags plugin. It adds a head_tags field for each entity, containing a list of head tags in JSON format, and it is intended to work with any SEO plugin that modifies the content of the <head> element.
The first version of the plugin was submitted on December 19. The WordPress Plugin Review Team told us that there was a problem with the plugin name and it had to be submitted again with a few changes.
After some delay, the final version of the plugin was sent yesterday to the WordPress Plugin Repository and it is still under review. As soon as it gets published we will announce its official release.