Theme customizer preview logical changes

Hi,
I have been trying to create way of refreshing the preview window using .previewer.refresh(); which works perfectly but I would also like to be able to automatically save specific or all values back to the database.

I have several controls which make logical structural changes to the template in php, because these are not sent back to the database they can not be viewed in the previewer without first being saved so would like to trigger a save action before triggering the refresh command.

Obviously postMessage is not what I am looking for here as I dont want to have to insert these changes via JS but a save and refresh would do the job.

Kind regards