Brion Vibber, 30/04/2014 21:51:
If there's interest in investigating this scenario I can write up an RfC with some more details.
I'd say just go on and update/replace https://www.mediawiki.org/wiki/Requests_for_comment/Standardized_thumbnails_sizes with your proposal. :) (And then mark it as accepted right away? :P)
Nemo