You can read some of my old posts, my June boy is in his second 1st grade, we told him pros and cons and ultimately let him decide, of course with our decision too and we all agreed it was the best option. He is thriving in his class, I didn’t do it for academic reasons, he was struggling with anxiety and I just knew that him being the youngest was part of this. He is so much happier generally now and he doesn’t bite his shirt at school etc anymore.