Change the theme and how tightly packed it is

Settings, General, Appearance. Both the theme and the density persist, and both apply the moment you pick them.

Last checked against the app on · View as Markdown

Steps

  1. Open Settings, then General, then Appearance.
  2. Pick a theme and a density. The change applies immediately rather than after a restart.
  3. Both are written to your settings file and read back next launch, so the choice survives closing the app.

How to tell it worked

Close and reopen the app. It comes back the way you left it.

If it does not work

It looks right now but resets when you reopen.
The change applies to the screen immediately and is saved in the background, so a display that is correct proves the first half only. A reset means the write failed, and that is worth telling us about.