So to beat 1.6 insanity i had to use a dumb strat that somehow worked, at the start of the phase 1 where it's frisk you want frisk to be down and all to the other way of the hall, then at phase 2, you want to keep chara down to the other way, to do so, you'll spam blue Bones, chara's ai will Always stop Moving when there are blue Bones, they won't try to dodge them, just make sur to not spam blue Bones too much, use a blue Bones every like 1.2 seconds, when you made sure that chara is all the other way to the corridor by using telekenisis (when your screen shakes that mean chara took a wall) just spam here with blasters, you want to do the same thing for phase 3, and for the last phase because your coldown are highly reduced you just want to do telekenisis and blasters unitil chara dies. Remember you need to get a bit lucky, but i've managed to beat insanity multiple Times with sans because of this technique. (Sorry for my Bad english, if you still can't manage to beat insanity 1.6 with sans add me on discord and i'll send you a full run)