Directional signage would be like a one-way door, but with less “forcing”.
With a one-way door, there is no going back. With signage, there would be a for example 75% chance of the sign being followed by pax.
However, manual signage is quite tedious, so I think you should be able to at some point research “adaptive signage” so that you can build screens with signs that you can control easily in a control panel with an “outline” view of your terminal which only contains walls and zones. Frankfurt airport has such “adaptive signage”:
In case some hallway is blocked, the screens can display another way. (This should be considered in the incident update)