SwiftData: How can I tell if a migration went through successfully?

I created 2 different schemas, and made a small change to one of them. I added a property to the model called "version". To see if the migration went through, I setup the migration plan to set version to "1.1.0" in willMigrate. In the didMigrate, I looped through the new version of Tags to check if version was set, and if not, set it. I did this incase the willMigrate didn't do what it was supposed to. The app built and ran successfully, but version was not set in the Tag I created in the app.

Here's the migration:

enum MigrationPlanV2: SchemaMigrationPlan {
    static var schemas: [any VersionedSchema.Type] {
        [DataSchemaV1.self, DataSchemaV2.self]
    }
    
    static let stage1 = MigrationStage.custom(
        fromVersion: DataSchemaV1.self,
        toVersion: DataSchemaV2.self,
        willMigrate: { context in
            let oldTags = try? context.fetch(FetchDescriptor<DataSchemaV1.Tag>())
            
            for old in oldTags ?? [] {
                let new = Tag(name: old.name, version: "Version 1.1.0")
                context.delete(old)
                context.insert(new)
            }
            
            try? context.save()
        },
        didMigrate: { context in
            let newTags = try? context.fetch(FetchDescriptor<DataSchemaV2.Tag>())

            for tag in newTags ?? []{
                if tag.version == nil {
                    tag.version = "1.1.0"
                }
            }
        
        }
    )
    
    static var stages: [MigrationStage] {
        [stage1]
    }
    
}

Here's the model container:

var sharedModelContainer: ModelContainer = {
        let schema = Schema(versionedSchema: DataSchemaV2.self)
        let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false)

        do {
            return try ModelContainer(
                for: schema,
                migrationPlan: MigrationPlanV2.self,
                configurations: [modelConfiguration])
        } catch {
            fatalError("Could not create ModelContainer: \(error)")
        }
    }()

I ran a similar test prior to this, and got the same result. It's like the code in my willMigrate isn't running. I also had print statements in there that I never saw printed to the console. I tried to check the CloudKit console for any information, but I'm having issues with that as well (separate post).

Anyways, how can I confirm that my migration was successful here?