Hi @Nuro
Good description, however, I am a bit lost due to not seeing the repeater field in question. Can you post some screenshots to help me see and understand how you want the data to automate?
My first idea is to hook into a WP action which is fired when WP creates an autosave post (when you first edit a new post). Your function could then just insert the default values and then when the page loads, your default values will exist!