You are correct with the unlimited hay, and if your bun is a juvenile (under 6 months) then he can have unlimited pellets too. Usually once a bun reaches adulthood, the healthiest option for them is to be fed limited pellets. It depends on your bun (size, diet and health history), but it seems like the norm is anywhere between 1/4-1/2 cups per day. Luna is 4.13 lbs. and she gets 1/8 cup of pellets a day (a little less than the norm because of her digestive history). As far as overeating stuff like veggies/fruit, if given the chance, any bun would probably choose veggies/fruit over hay. But hay is the most important part of the diet, so eating too much of something else will cause your bun to eat less hay. Veggies aren’t really an issue, but fruit is a very high sugar treat for buns, and should be fed sparingly. As far as overeating to the point that a bun will feel sick, well buns can’t regurgitate, it just comes out the other end
. So in that sense, I don’t know if overeating can really occur. And it is not really a concern as long as your bun is not eating a lot of something unhealthy or something that should be fed sparingly like treats.