I'm 100% aware of how FPTP works. I understand that if I vote for Claudia De La Crúz instead of Harris, that means Trump is more likely to win. I also know that if I vote for Claudia De La Crúz instead of Trump, that means Harris is more likely to win.

Given that I would never vote for either genocidal entity, I am not "taking away" votes for Harris. She can promise to sanction Israel or otherwise put an end to the genocide, and I would likely pivot to vote for her, as she would have fundamentally changed my single largest issue with her, despite thinking she has awful policy in general. However, this vote would be one she had earned, not regained.