ESP supports concatenated library for JCLLIB & TEMPLIB data set types using the CONCAT statement. It would also be useful to have the ability to concatenate DOCLIB data set type. DOC library concatenations do not work at this time because CSF EXTENTIONS BD and ED do not have codes to handle concatenated DOC libraries.
So, my enhancement request is simply to add support for concatenated DOCLIB to the CSF BD and ED CSF extensions.