Using this glitch I was able to get of Sandtrap, Ghost Town, Valhalla, Sandtoff and Last Resort. I haven't tried it with any other maps, yet.
1. First you must be in forge.
2. Go as far as you can until the barriers stop you.
3. Spawn a receiver and force it through the barrier (invisible wall)
4. While still holding the receiver save and end the game
5. Start the game
6. Spawn a sender node any where on the map and go through it.
7. Once you go through it turn into oracle and fly as far as you can go until you explode (die)
8. Go to theater mode and replay the game
9. Pause the video as soon as you die and go into camera mode
10. If done correctly you are able to go any where outside the map.
I did this on sandtrap and I took a picture of the da vince code easter egg that is next to each of the towers.
From what I know, this is the only way to get out of any map without mods.
I came up with this method of getting out any map. I DID NOT COPY IT FROM SOMEONE
When you try this on Ghost town or some other map it will be a little different than doing it on SandTrap.
Ex. On Ghost town you will have to force a receiver on top of the middle building. Why? So when you spawn a sender node and go through it. You turn into the oracle and stay up there until you explode. The key of this glitch is when you are next to the barrier and you explode with the oracle, you can go into theater mode and turn into camera mode to go through the barriers.
Makes sense?
I might make a video showing this. I'm not sure. Depends if I'm not to lazy to do it.
Sorry for the wall of text.