I doubt these monster Coast Guard ships are testing something as important as IEPS, given that there are so few of them.
There are those 2 smaller CG ships which should be doing that testing.
But thinking about it, the CG ships could be testing out a lot of subsystems and the internal below decks layout, given how much spare space they have. Here's a short list adding to PLAWolf's ideas
Propulsion eg. hybrid-electric drive with Li-Ion Auxiliary Power Units or propeller design
Hull form hydrodynamics
Electrical distribution subsystems
Aircon/cooling systems
Below-deck layout
etc
It's stuff that is not critical to the main function of the Coast Guard Ship.
There are those 2 smaller CG ships which should be doing that testing.
But thinking about it, the CG ships could be testing out a lot of subsystems and the internal below decks layout, given how much spare space they have. Here's a short list adding to PLAWolf's ideas
Propulsion eg. hybrid-electric drive with Li-Ion Auxiliary Power Units or propeller design
Hull form hydrodynamics
Electrical distribution subsystems
Aircon/cooling systems
Below-deck layout
etc
It's stuff that is not critical to the main function of the Coast Guard Ship.