The ImmediateInProgress setting controls when a batch in the Awaiting Index batch status queue is routed to the Index in Progress batch status queue.
By default, the ImmediateInProgress setting is set to 0, which only routes a batch to the Index in Progress batch status queue after a user indexes at least one document in the batch. This is also the default behavior if the setting is not present.
To route a batch to the Index in Progress batch status queue immediately after a user starts the indexing process on a batch (that is, immediately after a user right-clicks on a batch in the Awaiting Index queue and selects Index Documents), set the ImmediateInProgress setting to 1.