In the article Designing for iPhone Duo there is a section:
Consider using the full display width for interfaces where bars aren’t necessary. Some layouts can span the full display, which works well for visual, immersive interfaces that don’t scroll, as long as nothing conflicts with the Dynamic Island or the status bar. Calculator, for example, occupies the full width of the display. You can also combine both approaches, letting a background image or header span the full width while scrollable content stays inset.
However, in order to do this, you need to ignore the safe area.
This feels more like designing for a posture than designing declaratively. I want to use the full width on the iPhone Duo because I don't have any toolbars or tab bars and a symmetrical layout makes more sense. However the content is important, and if a new device comes out that might use the safe area, my full-width app might not be functional any longer.
What I would like is to keep using the safe area, but somehow tell it that I want a full display width while respecting a safe area that might block my content in the future.