How it is used can be inferred by the version and clients tools in use.
Version 3, channel access protocol, time series archiver, alarm manager, are SCADA tools and can produce DCS steady state co n trol.
SNL, scan records, scan tool in CSStudio, are state transition control.
The areaDector package adds DAQ for NDimensional data.
Model Based Control is done in different ways bit Matlab Middle Layer Toolkit is a good example for this type of control.
The most recent improvements are in beam related instruments that are FPGA based with GHz sampling rates and feedback or machine protection in the few microseconds to 100s of microseconds limited by the length of fiber and time through fpga nodes. For accelerators and science this Isa game changer.
Epics 7 and the pvAccess protocol support these new instruments with aggregated data sets, ND Array, table, image and statistics. This supports scientific data acquisition for experimental data and AI/ML.
It is difficult to get good information from this query on specific sites. The web site for EPICS does not attempt to list all facilities or users.
Good luck in your endeavor,
Bob