Not sure you are a person seeking employment, or an employer? I will just assume you are a person seeking employment.
Although I am not a full stack developer, I can suggest that you try the least educational level required, starting from Diploma then Degree.
Find out from job sites the educational requirements for a full stack developer job. They probably will look at the persons skills and experience, and portfolio as a F.S. Developer. And probably have a coding test to select the right person.
So I think educational requirements is really upto the company's belief in the value of Diploma & Degree.