Thank you for asking this question.
I have free choice for my roo a wild game bird maintenance feed, which does not have all the calcium that layer food has. Some parts of the country seem to have food made specifically for roos but I haven't found any in my neck of the woods. In fact, my feed stores are actually clueless about roo diets - one said to feed them scratch (in the mid 90s when 2 roos showed up in my yard and I had never had chickens before I believed this advice and that's what I fed them - luckily they also free ranged and I found them homes in 4 months, hopefully before too much damage could be done). Other stores say to feed them layer food. Advice I've seen given on BYC time and again is that roos should not have as their primary diet the high levels of calcium in layer food.
My roo and his hen friend (who always has layer and oyster shell free choice) also receive some sunflower and bird seed mixtures, fresh fruits and veggies, a little scratch, and when cold, something warm like oatmeal and scrambled egg (only because they won't eat oatmeal plain!), warmed butternut squash...or a bit of high quality grain bread but not too much because salt may be on the high side.
They also get Avia Charge 2000 in their water to help in case the ratios of things are not quite perfect. They also free range some of the time and eat whatever plants and bugs they wish.
My roo was in another's care for some months last year and while the promise of the above-noted diet was made, they reneged and he was only offered layer food. There is some belief that he made have sustained some kidney damage from excess calcium and his feet seem to hurt him sometimes. Some think he might have gout from kidney trouble and so I've been feeding him some black cherries to try to help with that. He does seem to get some relief. He was at this other place for maybe 9 months so hopefully didn't get too much damage but I'm just not sure yet.
JJ