Is reading in concurrent queue supported?

[jssez28]

https://www.mongodb.com/docs/realm/sdk/swift/advanced-guides/threading/#create-a-serial-queue-to-use-realm-on-a-background-thread

When using Realm on a background thread, create a serial queue. Realm Database does not support using realms in concurrent queues, such as the global() queue.

The documentation says does not support using realms in concurrent queues. Does this also include reading? I want to know if we need to use a serial queue even when reading in a background thread.