Plates are awesome for marking train station etc for what goods they have - gives a very nice 'display', easy to see in map view. I mostly use the medium but for boats in cargo ship I use the small on each dock to show what goods are there.. Get's important to get easy overview if you play modded Angel & Bob's, Py or similar that has tons of mats that needs shipping.
And it just looks cool.
Example on how I use this mod in current game https://flic.kr/p/2rdB7vB
