It already exists in mc_juice. It is called "Low%" https://www.speedrun.com/mc_juice?h=Low-RSG_4_With_Roots&x=zdnyg47k-wle9q2r8.z19o7z81
Thank you for the splitting! Here is my fast turn OoB run which I mentioned before :) https://www.speedrun.com/dfz/run/me9g2p2z
In my opinion, the sensitivity change seems pretty easy to detect so we may not need extra requirements. For example, if you compare my OoB wr (used higher sensitivity) and iLauu's 2nd place run (normal one), you will easily notice a drastic difference. It's so obvious.
Sensitivity changes with graphics quality change on some hardware. It happened on Bush_clover's, zayo's and my pcs but iLauu couldn't reproduce it. It's hardware dependent I guess. If so, it's unfair to compete between people with different sensitivity so I think some kind of rule change is needed, such as splitting or banning increasing the sensitivity.
F3 is very useful, but No F3 is so cool so I want it to become more popular :)