To me, 99.5-plus percent of the time, keeping the leading consistent is preferable for both aesthetic and practical reasons. However, in those instances of a single big headline on a poster or a print advertisement, or an art head in a magazine layout, it’s fine to do whatever is necessary to make the composition of words look even and balanced.
Thanks, that’s excatly how I feel.
Although it’s not often I run into these situations, I’d much rather go with something that looks right rather than something that is ‘technically’ right.