I know! ( •̀ ω •́ )✧
This choice option is only available if you aren't on anyone's route by the end of chapter 5.
The most effective way to do this is probably just go down to the planet assignment with the character you have the lowest affinity with. This should set it up so that you entirely bypass route-selection and end up on the "No LI Path" which will fully off ramp you by the end of Chapter 10.