Anyone thinking a protest vote will help anything should think about how much protest votes would have made Hitler pause.

Mussolini didn't even care about votes at all and just marched an army of supporters into the capital and the king went along with it because Mussolini said he could stay on as a figurehead.

Franco fought a civil war to bring fascism to Spain while the capitalist States in the area watched on (and Hitler and Mussolini helped).

Israel continues to get support from Western leadership despite many protests and demonstrations. Western powers haven't turned live ammunition on protestors yet, but they've done so in the past. I think the only reason they haven't is because they have more effective tools that don't generate as much outrage, but if those tools don't work, I believe they'll fall back to those methods.

The idea that a protest vote or boycott will help anything is naive with all of these examples of people who don't care about protest votes or even election outcomes when taking or wielding power. The amount of protest votes it would take to matter would be enough to win the election outright. They don't even have to do anything about them other than ignore them entirely.