Remember the power in these systems comes from a backup battery to make
it fail safe. It would involve major rebuild costs to do that.

Not true. Most of the systems that I have seen will automatically release the doors during a power fail. Since these are fire doors, the default is to close them in any "emergency". A power failure is considered an emergency and the doors are released.

As matter of fact, during a fire inspection we will trigger these doors in one of two ways: 1) Fire alarm trip and 2) power failure. In order for the facility to pass the inspection, both methods need to work.

Dan