There's a few area's where you are able to see outside the map

If you rocket jump up near the last point you are able to see through a small gap
setpos -1665.928711 462.827271 170.031311;setang 34.787579 -90.887657 0.000000

In Red's last spawn you're able to jump up onto the rafters above and see through quite a bit of the walls
setpos -584.389526 2024.848877 280.028137;setang 5.001964 -166.757660 0.000000