My DD had a lot more homework in 2nd and 3rd grade than she has now in 4th, and it was much more poorly managed in terms of how much time she had to complete it.

Your little guy has a long school day. Ours get on the bus at 7:30 for an 8:00 start and get out at 2:30 most days, and just after noon on Wednesdays. They usually stay at Boys and Girls Club until I can pick them up around 5:30 or 6:00, so they are gone for longer, but that sounds like a difficult school day for you to manage.