My family has one of the well-known single-site cancer-causing mutations; we know what the specific site is, even. It would be immense to "fix" (I am not a geneticist) that single site. Even just for my kids.
Why would you prefer the risks of editing versus the risks of preimplantation screening? Editing would be strictly riskier unless there’s really no alternative (unlikely but possible)
Preimplantation screening isn't an option for me or any other of my family members who are long past implantation. I'm not saying I'd hop on stage 1 clinical trials of a potential editing cure, and we'd have to see what the data on risk looked like to compare it with the risk from cancer without editing.