1 oz of pellets per 1 lb of body weight is too high. That would mean a 4 lb rabbit would get 1/2 a cup of pellets a day. That is too much.
Here is one set of guidelines regarding amount of pellets. It was written by the vet who sees the rabbits at the sanctuary where I volunteer.
Weight Daily pellets
2 – 4 lbs 1/8 cup
5 – 7 lbs 1/4 cup
8-10 lbs 1/2 cup
11 – 15 lbs 3/4 cup
That only goes up to 15 lbs, but some Flemish giants are that size, while others may weigh more than 20 lbs. Depending on the source, you will find different recommendations regarding amounts of pellets to feed a rabbit, but I have never seen any site say 1 oz of pellets per 1 lb of rabbit weight.
Pellets should be free fed until a rabbit is 6 months old, or a little older, then they should be measured daily and the bowl should not be refilled if the rabbit empties it. Rabbits should have hay available at all times. I have a New Zealand rabbit, who is around 7 or 8 pounds and she gets a little more than 1/4 cup of pellets a day.