The LineProcessors collection in ServiceOverrides is currently not shared between different implementations of IServiceOverrides in the same way that the Overrides dictionary is.

This means calling LineProcessors() on an IModuleConfiguration implementation does not affect the LineProcessors on LineProcessors, so custom line processors cannot be registered through a module.

Talking with @khellang, the preferred solution is to move the LineProcessors collection into the Overrides dictionary on ServiceOverrides.