In many places it is illegal, know your county/city/state laws first. What do you want to sell for? That has a point on it too. Pet people don't want older rabbits here, even if it is not the best for the rabbit. Some areas are the complete opposite end, older is better. Another thing is, what do you want to be known for? Word of mouth will make or break, even if just selling pets/food.
Kits are hardier if they are older, less likely GI upset and plausible death worst case. Not saying I've not had my fair amount of too young kits I pity bought or bought before I new better that didn't' do OK, its just it is a possibility. I've gotten some that didn't last the week and they were well of age to eat on their own too.
Are you working on any kind of showing? I don't know of a single show breeder that wants a bun less than 8 weeks, unless buying a doe and the kits. Show breeders often wait until 12 weeks or even 5 to 6 months to choose. I make my first picks of keepers at 8 weeks of age, obvious pets leave then one way or another or sex of what I do not wish to keep any way even if potential show/brood. Young ones are a gamble on how they will turn out.
My does wean at different times. Some as early as 4 weeks some would never wean.