how to work with TObjectManager correctly?

Hello! In my mobile application, I use one global TObjectManager for all search, insert, and edit operations! Everything works perfectly!
I saw recommendations that it is better to create a TObjectManager, do a data operation and destroy it.
Question: Please explain how to work with TObjectManager correctly?

The best approach is create one manager for each operation. Create the manager, perform one or more operations in a specific context (a transaction, a crud form, etc.) and then destroy the manager when it's finished. I advice against using global managers.