There are no ethical choices under first-past-the-post voting. We must instead make a decision that reduces the most harm.
That's not what harm reduction is. That's never how the term's been applied. I know language can change, but abruptly fabricating an opposite meaning in an attempt to dodge consequences for one's bad actions (potentially losing a campaign due to one's undying dedication to genocide and fascism) is not an appropriate treatment of the term.