Headless/Gutless Modules?

If I recall correctly, at some point we had the chance to create headless modules or modules without the Module subclass by instantiating the Model with the parent classes, e.g.:
Model * modelHello = createModel<Module, HelloModuleWidget>(“HelloWorld”); // gutless
Model * modelHello = createModel<HelloModule, ModuleWidget>(“HelloWorld”); // headless

I haven’t tried it before, but now surely this is not feasible (v1). The gutless version does not compile, while the headless fails an assertion during startup.
Is my memory failing, or has something changed? Is it still feasible at all? Has anyone ever used it?

The first is supported, the second is not.