I think it is, but not at the expense of selling out core ideas. But, I'm not a fan of the 'negative' vote, and not-voting is valid too. If I don't like either I just don't vote. I also fail to see where Trump is a 'vote against at all costs' type of proposition. He's very much like Biden on paper, sans the selling out to China stuff and the persecution of black people for minor crimes thing that Biden did in the past.
Yup, I'm not arguing around whether Trump (in particular), is a 'vote against' candidate. We differ on that, which is fine. Just the general premise.
And yes, I've put in blank votes before, where I couldn't find a candidate I wanted to support.
And I've voted third party on occassion, even knowing they 'wouldn't win'.
Though, we have a preferential system here, so every vote ultimately counts.