This is almost impossible.
In UE3, some places used blocking volumes for their invisible walls.
In most occasions, it was a separate file (like in Jadestone village).
However, some were part of the floor and/or wall, being in the map itself (like in Zaiwei).
In some places, those blocking volumes were part of the place (like in Outlaw Island - Juna).
Without the "invisible wall" there, you are stuck falling forever.
And then, there's another type of invisible wall: the server-side.
These are places where the server says that it is an invalid position to be, so you get rubberbanded back to the "right" place.
This happens a lot in Khanda Viar and The Scorching Sands.
The blocking volumes are possible to re-color, but a massive pain in the ass.
The server-side stuff is impossible, and that is actually the most annoying one, which is the type that teleports you back.
Why is it impossible?
Because if they existed in the files as invisible walls/blocking volumes, you wouldn't be able to step on them in the first place,
In UE4, something very similar happens, but it's just everything in (possibly) the same .pak file.
