I was wondering if there would be a point in creating a set of diacritics for English with the goal of making it easier for children and adolescent or adult learners to acquire proficiency in reading and oral comprehension, think niqqud in Hebrew. It seems someone put this idea into action - they called their project FUNetix: https://funetix.org/home-2/
However, there is no research on the results. Bummer.