@MommaSoaper Many of my highly-sensitive-skin family members and friends use my soaps, all of which contain SC. No one has reported a problem yet with any of soaps in terms of irritated skin, rashes, etc.
I personally have super sensitive skin as well - if someone would have an adverse reaction, it would be me. But I have zero issues with it.
Most of my soap users live in hard water areas. For them, adding some kind of chelator such as SC or citric acid (which the NaOH will convert to SC) is necessary to achieve nice lather and lessen the soap scum on the showers and sinks. Without a chelator of some sort, many of them cannot use handcrafted soap for those reasons. SC also protects against rancidity/ DOS, which can be helpful if your users aren’t aware of proper use and storage of handcrafted soaps.
All that to say, if you are making soap just for yourself, and don’t live in a hard water area, then a chelator may not be needed. But if you plan to share it or potentially sell it, without a chelator, you may lose fans and customers who do have hard water, because they will struggle to work up a nice lather, and they will hate the soap scum buildup, too.