Occasionally, a modder wants to disable the vanilla GUI for an entity and replace it with their own.
This commonly occurs when they want to remove some part of the vanilla GUI to reduce confusion (since it is not possible to edit vanilla GUIs directly). For example, the Radiation-proof Inserter in the Cerys mod disables the GUI entirely because its custom logic conflicts with the player being able to set circuit settings. Ideally, the inserter could have a GUI of its own which intercepts the vanilla one.
It would be a huge task to replicate the entirety of vanilla entity GUIs, but a more feasible task is to make a 'barebones' entity GUI in a library mod for mod authors to extend.
To complete this bounty, a barebones GUI should be provided have a proper frame, title, close button, entity status and entity preview, with similar styling to vanilla Factorio. It should automatically replace the vanilla GUI in a simple way, the developer should be able to attach their own children to the interior.
A published or draft mod is acceptable. However, please note: library dependencies, for them to add value, should be very clean and stable, but also allow flexibility and don't introduce too many unnecessary layers of abstraction.