Can an attacker Crackshot cancel a die Palpatine has changed to an evade?

Yes

Yes, Crack Shot is used at the start of the “Compare Results” step which is after Palp has already taken affect.

Thanks. I found the FAQ. " Adding or subtracting the number of dice that are rolled (e.g. through Jan Ors ) and canceling die results (e.g. through Crack Shot ) do not count as modifying dice. (FAQ, v.4.1.1, 3/15/2016) " Someone should add that to the Crack Shot page on Fandom.

What is Fandom?!

X-Wing Miniatures Wikia

COngratulations, you're someone