But at least one could already play stuff like Animatch or Neverball at full res on the phone with no glaring issues.
Today, while still not ready to become the default (almost!), SDL got bunch of those missing parts filled in - mostly by Ethan Lee. I've managed to find and fix some bugs this time as well. So, grab SDL 2.0.16, test and enjoy its refreshed Wayland backend while it's hot!
More info on the Wayland backend state (by Ethan): https://icculus.org/finger/flibitijibibo