We did not apply for APS preschool because our base school does not have extended day for 3yr olds. Having had my newly 5yr old kindergartener at extended day for 2 weeks now, I am not sure I would want to send a 3 or 4yr old. It’s managed chaos and it seems like a kid needs to be old enough to self-advocate if needed.
My neighbor has her daughter in the Montessori preschool program and she worked freelance the year she was 3 and then started extended day when she was 4.