If you want to use the portion feeding system, it will take some trial and error. Depending on the breed.
Start by feeding a healthy portion, 2 quarts of feed in the early morning. Watch to see how long they take to finish it. If they gobble it down in 20 minutes, you'll need to feed 2.5 quarts the next morning. The goal is provide slightly "more than enough" for the morning feeding.
Once you've established what they need/want in the morning, look and see how long it takes them to finish picking the trough clean. Noon? 2 pm? That would be my goal. You know you've fed them enough for more than half the day.
Then, feed a smaller portion around 5-6 pm. This portion needs to be smaller and needs to be cleaned up completely within the hour. The goal here is not to have any feed remaining through the night, which tends to encourage visitors of the rodent variety. This puts them to bed with a full crop.
Try the system. See if you like it. See if your hens like it.