Quickstart on settings
Project vs. Timeline Settings
By default, Project settings apply to all Timelines in the project. To change that behavior, you need to use the method Timeline.custom_settings(True). This will allow timeline settings to be independent from the project settings. You could then have a Project resolution of 1920x1080 for example and a Timeline resolution of 3840x2160.

Literals
Whenever you see Literal on the type hints in the documentation, it means that the values listed need to be literally as shown. These literals were gathered by testing which settings are valid on the interface.