New installer: Silent and attended

I am starting a new Setup Factory 9 project and am not sure how to create an installer that will be used normally and silent.

Looking at the forum and the documentation I am aware that:

1. Silent Install does not load screens nor execute events associated with screens
2. Silent install will only execute the following scripts:
   1. On Startup
   2. On Pre Install / On Pre Uninstall
   3. On Post Install / On Post Uninstall
   4. On Shutdown

Where would I then do the work, actually installing the application while supporting both silent and attended install?

From the docs:

• The On Pre Install event is triggered just before the installation enters the install phase and begins installing files onto the end user's computer. This event is fired right after the last screen in the Before Installing screen stage is displayed.
• The On Post Install event is triggered after the install phase of the installation has been completed, right before the first screen of the After Installing screen stage is displayed.

The part that is not clear is if the "On Pre Install" script starts executing and then the "While Installing" screen will be shown while the "On Pre Install" script executes or will the "While Installing" screens only be shown one the "On Pre Install" script has finished execution.

Since the silent install does not show the "While Installing" screen, the "On Progress" action of the screen sounds like it is definitely not the correct place to do the actual work.

Where is the correct place to do the work of the install then?

PS: Doing the work refers to running scripts that take time and performs actions, that must show progress to a user when attended install.