We are having following scenario. Need to come up with good architecture.

The application is heavily used as frontend. The nature of application is data entry.

The number of screens would be less than 10 but each screens functionality rich, which would contains 100s of inputs & screen business logic (validations)

Now the application development is in halfway, however the frontend module becomes heavier. Opening a module and working in design time becomes slower.

Hence idea has been proposed to split the end user module into pieces to improve the manageability. Also provide help to developer to work in different screens independently (to avoid work on same module at same time)

Option 1: 

Create different end user module for different screen of functionality. Orchestrate application with one end user module by referencing screens from different end user module.

Note that screens are weak references in OS11, so we will not violate architecture rule of side reference in UI layer.

However, we will have to handle authentication, client variable and other common things separately for different modules when user travels across the screens (modules)

Option 2:

Create screens as blocks in core widget module (XXX_CW) for each screen and refer it in end user module.

The downside of option 1 will not be here as we use one frontend module to serve the users. 

In your opinion which option is better? Is there any other option we have?