Otherwise it's impossible to only download non-DASH formats, for example `best[height=?480]/best` would download a DASH video if it's the only one with height=480, instead for falling back to the second format specifier.
For audio only urls (soundcloud, bandcamp ...), the best audio will be downloaded as before.
It doesn't work well with 'bestvideo' and 'bestaudio' because they are usually before the max quality.
Format filters should be used instead, they are more flexible and don't require the requested quality to exist for each video.