Area transition random encounter mechanics (BGEE v2.5)

[GrErA]

Hello,

I am trying to figure out exactly how random encounters from area transitions work in Baldur's Gate Enhanced Edition (v2.5, if that matters). Specifically, how the game determines whether and which "waylaid by enemies" encounters happen when the player goes to the edge of a map and tries to travel to some other area.

I'm familiar with tools like Near Infinity for accessing / reading game files, but am not sure where to look or how to interpret files like arealink.2da (or even if this file relates to what I'm asking).

Thanks for any help.