From the MVS Initialization and Tuning Reference
manual in the MVS bookshelf:
21.0 Chapter 21. CSVLLAxx (library lookaside (LLA) list)
Use the CSVLLAxx member to specify which libraries (in addition to the LNKLST concatenation) library lookaside (LLA) is to manage. If you do not supply a CSVLLAxx member, LLA will, by default, manage only the libraries that are accessed through the LNKLST concatenation.
and from the Using CICS
manual in the CICS Tranaction Server bookshelf:
Using LLA (MVS library lookaside)
Modules loaded by CICS® from the DFHRPL libraries may be managed by the MVS™ LLA (library lookaside) facility. LLA is designed to minimize disk I/O by keeping load modules in a VLF (virtual lookaside facility) dataspace and keeping a version of the library directory in its own address space.
LLA manages modules (system or application) whose library names you have put in the appropriate CSVLLA member in SYS1.PARMLIB.
So yes, LLA / VLF applies ONLY to load modules (both in PDS and PDSE), and VLF is the dataspace used by LLA.