There could be the possibility to select whether the dark/light mode variables are set in Theme Editor. For example, to have a dropdown with 3 options: Dark, Light, Auto (automatically set by the platform, as it is currently).

This could be useful for instance, when the header/background colors are dark enough to have white text, but a light-mode is active nonetheless, with dark text. Or just because, to give more power to the developer to adapt the apps.