S2PX requires a solution which supports the same capabilities as Server hashed files:
A single hashed files can act as targets and sources within the same job.
A hashed file can use keys values to enable the upsert of its data.
Hashed files provide database record locking so that a single job or multiple jobs can read from and write to the same hashed file concurrently.
Commonly considered hashed file alternatives such as sequential files, data sets and file sets do not support the functionality described above.