It is not true that 1 oz ppo is wrong, even following IFRA recommendations much more can be used with some fo's. I use 1 oz ppo of oils and may normal is 1.1 oz per lb of oil which is the rate I used since I started making soap without problems, this excludes cinnamon and clove since they can be very irritating and so EO's that are just extremely strong with Thyme coming to mind. I also do not buy fo's that have very low IFRA ratings, knowing I will end up with soap that does not have much scent in a very short time.
First off, as DeeAnna said, it it the soap burning the eyes and any soap will. You can cure a soap for years and it will still burn the eyes. It is soap
Soap is also not good for hair so put a lot of thought behind thinking you are going to sell soap as shampoo. If you have a customer with long beautiful which is not cut often and you sell her soap for shampoo you could end up with a very unhappy customer because her hair became damaged and she had to cut it off. Think Chaz Dean and his Wen products, he settled a lawsuit, for $25 + million and has removed his lye based shampoo. What is now sells is a surfactant based lotion. This is a person that should have known better than sell soap for shampoo. No tear shampoo are made with surfactants which tend to not burn the eyes. As mentioned, think baby shampoo.