Hello. Thank you for contacting the Toolset support.
Well - as I understand you would like to integrate REST API support for your custom post type. There is no native feature available to support REST API and output your result as JSON.
This needs custom programming and that is beyond the scope of our support policy. If you need custom programming for your project, please feel free to contact our certified partner.
No I do not want to "integrate REST API support for your custom post type", I mealy want to use WP-Types to build a bit of output in the Head as json rather than as HTML in the body.
I would think this would be fairly strait forward for wp-types to enable if it does not already do it. I can already add this to the body using wp-types... why would you not want to do this in the head as well?
Well - we do have plans to integrate REST API as well but it will take time.
Regarding - adding the JSON output in head section, there is no such feature available and why we didn't add such output within head section is depends on our developers as they are the right person decide what we should include and what not.
But - I will forward your concern as a new feature request to concern department for assessment but please note that there is no ETA on it.