For example, if I have to go to work in an hour and wanted to find a 1 hour OVA/movie to watch, I think it could be helpful as a very low-priority suggestion to work on eventually.
A duration sort is already a part of the backend, but is not a part of the frontend yet.
You can for instance do this:
https://anilist.co/search/anime?format=MOVIE&sort=DURATION_DESC
https://anilist.co/search/anime?format=OVA&sort=DURATION_DESC
Or, in reverse order (but then those without a duration are listed first):
https://anilist.co/search/anime?format=MOVIE&sort=DURATION
https://anilist.co/search/anime?format=OVA&sort=DURATION