Young rabbits need lots of food to grow properly. A 9 week old bunny still has lots of growing to do.
I would free feed, but give measured amounts so you know what he is eating. Start with 1/4 to 1/2 a cup at a time and fill as needed. As he gets used to that amount, you will be able to monitor him better. If he doesn't eat all the food in his normal time, then it could be an issue. If he starts to eat all of it quickly, he may need more. If you are just giving a bowl full, it is hard to tell when they are not eating.
Make sure he has hay as well. Rabbits need hay to help grind down the back molars and it helps keep the gut moving. If he is not eating hay, cut back on pellets a bit. The hay should be alfalfa now, but you can give timothy too. Once he is about 6-8 months old, switch to timothy or other grass hay and cut out the alfalfa.
Since English Spots are not a huge breed, I would free feed until about 6 months, but continue with alfalfa until about 7-9 months before switching to timothy pellets.