I spend most of my days trying to find or to resize all the posters of my libraries to a proper 2/3 ratio. It can be fun but it can also be very tiresome. I wonder if it wouldn't be possible to add an algorithm to Plex to (optionally maybe) automatically resize the Posters for movies and series to fit the full display card.
Ideally Plex would choose by itself the pictures which are already at a proper ration among the posters for less resizing but that's asking a bit more. I think a simple resize of the poster chosen as an optional advanced option in the library settings would be very handy.