I am giving my runners 2/3 maintenance ration (16% protein), 1/3 layer pellets (20%) a large handful of cat kibble per two to three pounds of pellets, free choice oyster shell.
I make some variations in their feed, depending on how the eggs look and how they behave. For a few weeks I have sprinkled a few tablespoons of oyster shell in their dry food, because we had a few eggs that were very thin shelled. If I don't get them into the garden during the week, I add some chick sized grit, since their substrate is sawdust and coir in the day pen.
Their eggs are coming out at about 50 to 60 grams, with the occasional 90 gram double yoker. They are just about jumbo chicken egg size, it seems to me. These are runners, as I mentioned, and I have read that their eggs are close in size to chicken eggs. I have read that Wifezilla's runner laid large eggs, I think.