The Dev Guide for CMS 12 says this regarding Initializing the CMS (here):

Custom initialization logic can preferably be done through standard ASP.NET 
Core components like for example IStartupFilter or  IHostedService. The 
IInitializable system (described below) within CMS that was built for 
ASP.NET - where there was no central Startup class - is also available in 
ASP.NET Core application and can be used also.

Has anyone successfully converted an InitializationModule with events into standard .NET Core components? I found an add-on where the Initialize() method is called during Startup/Configure() but it doesn't use an Uninitialize() method. IHostedService only has StartAsync and StopAsync which might* be comparable to Initialize() and Uninitialize(). (*I'm still learning about IHostedService.) 

I have a couple of questions then:

1. Where in the application's startup pipeline is Optimizely's InitializableModule called to set and call Initialize() and then Uninitialize()?
2. Is IHostedService.StartAsync/StopAsync the same as Initialize() and Uninitialize()? If so, I can follow the instructions in the link behind IHostedService above.
3. Also, if it's the same, do I call it in Startup/ConfigureServices() or Startup/Configure() in Startup.cs or somewhere else?

Questions 1 & 3 could be answered if there's a diagram of the startup pipeline for CMS 12.

Thank you!!