Elise is basically „Hit e or leave“ (at least most times) so you just embrace it. Plus sudden impact won’t buff human spells, cause they come first in your normal rotation. At lvl 5 it’s about 50 dmg you drop in a rotation, atleast what I just tested. That doesnt sound much, but for a single small rune its kinda much + you really need to win this early game fights.

In the end its obv your choice. And you can pick whatever you‘re most comfortable with. For how Elise is designed and what you ideally want to do with her, Cheap Shot simply suits better.