Okay, I took the time and created a code that can reset FOW. I used remastered bitmasks (which is now supported in 1.16.1 using the new enabler). You can see the source codes here. Attached is a map with 2 areas. Step on the light one to remove FOW, on the dark one to add FOW (to restore using default FOW you must edit the source code yourself - change one "false" to "true", not that hard to do). Funny thing is, we cannot manipulate tiles in remastered, not even those flags. It's possible to rework the copiers to counters, but it's a waste of time and space.