Pellets for 3 week old orphan bunny - how much?

Hi,

I'm fostering 3-3.5 weeks old orphaned baby bunny. He stopped drinking KMR formula ~2 days ago.
He's eating hay, drinking water and I give him Burgess Excel pellets. He can eat about 10g in 12 hours.
He's feeling well, binking, eating, drinking and pooping normally.

I think he could eat about 15-20g of Burgess Excel pellets per day, but I'm not sure if he should be given that much.
Should I give him only a specific amount of pellets, or give him as much as he wants?

Thank you in advance!

I think letting his appetite govern the amount is the best way but as long as they are putting weight on gradually then go with your gut.

Can we please have photos of this baby bunny? I love baby bunnies