Simple one:
The stairs at Slagworks.. u can walk through them from behind. Just walk in them so far that u can hit the players fighting at the flag (or heal ofc) but you will still be able to step back and get away unharmed when someone tries to kill you. They won't be able to walk through the stairs from the side of the flag.
So just stand in the stairs from the back and heal/dps and step back when you want to.
Hope this helps some people with taking Slagworks!