I really like having to “choose” my favorites. I like the idea of other people having a set of favorites emojis, and wondering what they are. Having only a handful to “choose from” (at any given time) really forces me to simplify my emoji usage and lends to more transparency by having a developed usage pattern.
Discussion
Just like “+” triggers the default “like” reaction, maybe “v” in the buttons list could cause all buttons after it to be presented in a dropdown menu for user customizable better layout.