In think you hit the nail on the head for me with this one:

I wouldn't be a Kamala supporter, so it doesn't benefit Trump

I'm in the same boat. Many of Kamala's policies aren't things I want or agree with. Many of Trump's policies aren't things I want or agree with. I disagree with BOTH of the major candidates so much that it doesn't make sense for me to vote for either of them.

They aren't losing my vote, their platforms are such that neither ever had my vote to begin with. It's not like my vote would have been for Kamala, but since I have a small issue with one of her planks, then I'm throwing a fit and I'm going to vote 3rd party.

Neither major candidate deserves my vote, In fact I think the difference between Kamala and Trump winning is relatively small for the US. Either of them winning will be a nightmare for the US. They're both terrible people, they may lie about different things, and the media favors one or the other more for their own benefit. They're both authoritarian warmongers, who say whatever it takes on the campaign trail to get elected, then stomp all over regular people when they get into power. The major parties are not the same, but they're both fucked.

I also happen to live in a state where one party will get double the other party's votes, and it's been that way for nearly my entire life. MY VOTE FOR PRESIDENT LITERALLY DOESN'T MATTER HERE, EVEN IF I LIKED ONE OF THE MAJOR CANDIDATES.

If other people like Kamala more than Trump, enough to cast their vote for her, then I encourage them to do so. I understand in swing states where individual votes aren't annihilated by a supermajority that people may have to be more strategic in their voting and take the bad with the good.

But personally, I vote for a 3rd party candidate with no chance to win, whose platform I happen to agree with more than any other candidate, and I can live with myself and the eventual outcome.

I definitely agree on getting out of first past the post though.