Migrating AMPTrackingOptions

I'm going to prepare slowly without changing it to Swift right away.

But I have a question.

I applied the option to 'AppDelegate' as above.

And it's in the Document.

What I'm curious about here is

1. Do I need to create and manage a shared class for the generated 'amplitude'??
2. Or is 'Amplitude' shared? (Anywhere you apply the option, does it apply everywhere??)
3. How do I apply 'disableLatLng'? Documnet not found..
4. I've never used 'defaultTracking' but should I just apply the option as shown in the document??

There are many parts that I don't understand even if I look at the document because it's still Newbie.