I don’t follow exactly what you’re asking. As I understand it the default (not transient) just means that the property won’t be skipped when, for whatever reason, its containing object gets serialized. The serializing context might be in-editor (saving/loading assets to/from disk), it might be a save/load game situation, or potentially anything.
If you can clarify your question I may be able to help, but then again I may not. There’s a lot I don’t understand about this stuff.