My personal experience: My Enchi female (that I got as a hatchling) grew incredibly quickly. All I did was feed her appropriately sized meals every 4 days until she was big enough for small rats, then fed her small rats weekly until she was big enough for mediums (weekly with those as well). During that time, she didn't refuse a single meal, and was up to 2000 grams by the time she was 14 months old. She's slowed off considerably since then (she won't be 2 years until January), so I've backed her down to small rats weekly when she wants to eat. While she was growing, though, I didn't hesitate to let her "pack on the pounds" as she saw fit.
Sounds like my piebald. She eats like a pig ever 4-5 days and has never once refused for me. She's finally on small rats after getting big enough from mice