EQClassic - Line of Sight

I have resumed working on EQC again, but my work right now is purely conceptual (I will not be producing source revisions). More specifically, I am rethinking our line of sight (LoS) system and I am also investigating the possibility of preprocessing a zone's LoS data. I am not terribly optimistic about my success in the latter, as the number of possible line of sight calculations for a typical zone is roughly 1.6E18, but if I can successfully collapse a zone into two-dimensional space, then there exists some measurable chance of success.

Regardless if preprocessing the LoS data is feasible or not (I am strongly leaning towards 'not'), my primary interest is replacing the core of our LoS system. Right now, our LoS system is based on EQEmulator's approach, which steps along a vector between two points and checks for a collision with the zone's geometry data. This approach is functional, but it is slow and I am not convinced that it is precise enough to be reliable. I believe a more elegant, efficient solution exists.