While on a spysat-mission with a single small ship, I got ambushed by a bigger fleet and so tried to disengage.
But when I spawned in the battle, there was immediatly an asteroid in front of my ship, as big as the whole ship. (The nose of the ship was practically touching the asteroid.) So I was completly blocked, needed several seconds to get somehow around and at this point, the enemy fighters where already all over me and the ship exploded.
So the suggestion is that when a disengaging fleet is deployed, there should be a check before, so that no immediate obstacle of the same size are placed in front of them.
Otherwise, the attempt is pointless.