$request Variable is not available in the ReverseSync Sync Step (4286644)

While configuring a workflow, you may notice that the $request Variable available for the ForwardSync Step is not available in the ReverseSync Sync Step.

This is by design. 

The Forward and Reverse Sync Rules do not share the same Hash table. Each rule has its own table, in the current design of the product the Attribute values are calculated very early in the process (before the actual Target Hash table is prepared/generated). Therefore the a $request Variable available for the ForwardSync Step is not available in the ReverseSync Sync Step.