I actually do have a mini project on the side to address this. It'll be posted to my twitter @needs_bear when it's ready.
Though there's no ETA on it as the main artist for Ember, Plaster, and Aaron is busy juggling work, life responsibilities, and the project. I won't spoil anything, but this was something I planned as an additional story to the game to help show a bit of Plaster's side as well as his current fate after the ending.