Hmmm... I was thinking. How does the border look? How's security? Would an Invisible, Levitating Wilco get through? 
the border itself is similar on all the sectors - it is a 50 meters wide no-mans land with security measures on each side. on the CAS side the fence is up to 10 meters high fence with three man patrols plus dogs and lots of sensors on the fences. On the EssEss side the fence is elctrified, plus a monowire on top. Oh yes and lots of mines. The security patrols are light scout ground and air vehicles plus of course so-called civilian operatives (also known as Wildcats commandoes)
the checkpoint is on both sides, although the checking is done usually on entrance to the secotr not on the exit in intra-city travels. There are 5 guards on the watch currently.
By your security system knowledge, chances for slipping through the checkpoint via invisibility are small, with levitate are none, and returning will be even harder - with Wildcats and their watchers around.