one note of context on:

> We should not introduce the ability to arbitrarily change the tile size independently of scale -- it breaks the contract with the designer introducing ways to alter a design dramatically beyond the original intention.

I'm imagining very soon Mapnik/CartoCSS allowing something like `text-wrap-width:@tile_size/2` where `@tile_size` would be known and provided on the fly by tilelive-vector.