Looks pretty cool I haven't played FC5 myself, nor am I familiar with FC modding, is the Stealth Mode stock content or did you implement it yourself?
Some feedback after having watched the playthrough:
I only watched the playthrough, but I'm assuming the level is non-linear (at least to a degree). I think what was lacking overall was (a) point(s) of focus/direction. There's hardly any contrast in lighting while a night theme would be especially suitable for this! The mood is nice overall, but overall little stands out to guide the player.Since it's an escape scenario, it would be helpful to give the player a glimpse of roughly where the extraction point is in the beginning of the scenario (for example, a distant guard tower with searchlights next to the entrance/exit of the compound).
Keep it up!