Jumbo-fying Custom Emojis

Some custom emojis look better at larger sizes. Because of that, I think it would be a good idea to have a way to show emojis at their full size (128x128, or whatever that emoji's actual size is). For example, maybe typing :emoji_name::jumbo: would display the emoji at full size, similar to how you can alter the skin color of certain standard emojis by appending :skin-tone-(1~5):. This might mess up text, however. So to avoid that, perhaps it could be limited so that it only works if the emoji is on its own line, or is posted on its own.