After conducting user interviews, a UX Designer finds an equal amount of users prefer to...

The one token and one utility class that should be suggested to the developers to ensure custom components respect the density settings are:

varSpacingMedium. This is a design token that defines the medium spacing value for the vertical and horizontal spacing between elements. This token can be used to adjust the spacing according to the density setting of the user. For example, if the user prefers the Comply density setting, the token value will be 16px, and if the user prefers the Compact density setting, the token value will be 8px.

slds-p-around_medium. This is a utility class that applies the medium padding value to all sides of an element. This class can be used to add padding to the custom component according to the density setting of the user. For example, if the user prefers the Comply density setting, the class will apply 16px of padding, and if the user prefers the Compact density setting, the class will apply 8px of padding.