I would recommend you try increasing the number of threads used (Options - Advanced - Thread Count). I know the dialog says it's for backup, but my understanding is it applies to File Restores as well. There is a lot of file IO latency when running APIs over the internet to grab each object in cloud storage and start the restore - as opposed to local disk access or even local network access where latency is low. Increasing the thread count will allow the backup process to run many object restores in parallel and reduce the latency impact.

Later this year, we will be introducing a new feature that will eliminate the IO latency issue for customers. For now, though, the best option is an increase in Threads.

Let us know how it works out.