The addition of trackers to hunt down forested areas around escape points could help increase the amount of interaction that players have against OPFOR, as the last few times my group ran the mission, we only encountered 3 squads. Another addition would be enemy PT boats paroling around the water escape routes (Such as the Hanoi, Sihanoukville etc...) , since once the players have entered the escape vessel, there is a considerable downtime in which there is no action. The addition of more enemies in general could have raise the difficulty, as 2 players can easily wipe the current amount of infantry. I'm not sure if these next few are already added or not, but adding virtual supports to OPFOR such as artillery could assist in firefights with the ai, as well as patrolling helicopters (but I haven't messed around with OPFOR helos much as of now)

On a side note, I ran into a glitch during spawn where I spawned on the other side of the map from my group, may have something to do with late joins when the mission had already determined my spawn. however, I do enjoy the aspect of having players regroup before setting out to escape, even if it is just 1km or so apart.

These are al just some ideas, each adding flavor to the escape mission. Hope these ideas help