> Sure, you have to transform the coordinates to the output. But still, better to render fonts at the final resolution; they'll always look better than if scaled after rendering.The font will look better but you have zero guarantee that the subtitles will be better too. Furthermore, you will lose any artistic value that the creator intended.
For example, go get the Russian movie Night Watch and watch it with the original subtitles hardcoded and as a separate file. The director insisted on doing the subtitles himself and he used them for great artistic effect throughout the movie [1]. Watch it with scaling and aspect ratio stretching to see how nicely rendered, crisp high resolution fonts can be inferior to a pixelated, stretched version created with intent by an artist.
[1] http://readingsounds.net/wp-content/uploads/2015/12/NightWat...
