Selectable emote sizes in chat.
Occasionally emotes contain text and letters that are a bit hard to read. I know Twitch accepts up to 112px emotes, but seems to use the smaller ones in chat. Simply having a little checkbox to show larger emotes would be super helpful to those with limited sight.
I don't even have that bad of vision, just a minor astigmatism and near-sightedness, and I don't know how many times I have used the zoom feature of my browser just to read the words in an emote.