- Larger text in the setup application.
- Extra setup application option of "fixed background".
With fixed background set you can no longer use the "floating" option. With this option selected the background is fixed when you start the game, therefore changing the screen settings in game no longer affects the background. This will probably be most noticeable when running in a window or if you change the colour scheme in game (the background will no longer change, e.g. scale or change colour).
Additionally, while playing a board it adds a very simple sky box around the board. I believe this should mitigate an issue on Steamdeck where the background leaves trails of previous frames (as you will no longer be able to see the background), although apparently turning off active lighting has a similar result.