There really isn’t a simple way to do this.
The biggest problem is choosing to save it as a draft or to publish it. This could potentially be achieved in your acf/pre_save_post filter https://www.advancedcustomfields.com/resources/acf-pre_save_post/. You wold need to test every field to see if something is missing and decide at that point if you want to create the post as a draft or publish it.
In order to do the above you would need to disable all of the built in ACF validation. Every field would need to be created in such a way that it can be submitted empty. You can’t have any required fields and you must allow all values to be NULL or empty. In order to do any validation on submitted values you would need to build all of your own acf/validate_value filters for every field https://www.advancedcustomfields.com/resources/acf-validate_value/ and you’d need to take into account that a field could be empty and only check validation if the field has a value.
Depending on how many fields and the type of fields involved this could be a large and complicated project, or not.
Welcome to the Advanced Custom Fields community forum.
Browse through ideas, snippets of code, questions and answers between fellow ACF users
Helping others is a great way to earn karma, gain badges and help ACF development!