How often do you feed your flock treats? Like table scraps, meal worms, ect?
The 90/10 rule makes me think that once a week would be good...?
I am just coming up on my first full year of owning chickens, so take this for what that is worth. Also, if you are planning to depend on your chickens for money, also ignore this.
I think the 90/10 rule is bullshit. At best it comes from data based upon battery hens in commercial environments where the primary motivation is maximizing egg production. When you are running 100+ hens slight variations in egg laying can add up.
I believe for the average backyard flock owner (I have 11 hens and a rooster) any reasonable feeding strategy will suffice. This summer I fed my flock green weeds that I pulled from my land everyday. I also started running all the compost piles through their run. I gave them a half cup of scratch everyday and kitchen scraps as they were available. My wife also took to ordering extra pancakes at our breakfast places, because she thought it was funny to watch the chickens eat them.
There were some days where I know for a fact, that they did not touch their commercial food. If I had to assign a percentage I would say that this summer easily 60% of their food was from sources other than commercial feed. Some weeks it was closer to 90% of their food from other than commercial feed.
Once they started laying, I was averaging 8 eggs per day from 11 hens.
This winter (I live in Minnesota so we have dark cold winters), I have been getting an average of 3 eggs a day. I don't heat and don't supply supplemental light. I give them (5) cobs of corn each morning, kitchen scraps as available, and 3/4 of a cup of scratch. I would say that over the winter about 70% of their food comes from commercial feed.
My conclusion is that a recreational flock owner can use almost any commonsense feeding strategy and have acceptable results. I would also informally argue, that the quality of life of my flock benefits from feeding them a diverse diet. Yesterday I gave them about half of container of Carl Buddig sliced ham, something about watching a hen running away screaming to hide in the coop with a full slice of ham so she doesnt have to share just makes me laugh.