As for finding available objects (including doors) that can be placed in a zone, I describe how to find them in this post:
http://www.eqemulator.net/forums/showthread.php?t=25420
As for working on doors in newer zones, I have added in doors manually to dreadspire, but that is all I have done so far. I never actually played in the zone on live, so my doors probably are not near 100% accurate, but good enough for what I am doing and I feel that they look correct.
It would be much better if someone could get packet collects from these newer zones to pull exact info for doors like CD did for PEQ database in the other zones. But, I don't know how possible that is now since the packet collector that was working then probably never caught the later zones and I don't think there is a current working one.
Adding them in manually is somewhat time consuming, but it isn't too bad once you get the hang of it. Mainly just going around the zone and getting a bunch of locs and then editing the DB over and over until they are just right. I think the hardest part for Dreadspire was getting the secret doors to be exact enough to not be noticeable right off the bat. Unfortunately, if you have advanced lighting on, they stand out horribly anyway even if they were perfectly aligned.
Sorry to get off-topic with this post. It would have been better if Chaos had started a new thread, or continued the one that I posted above.
As for this LoS fix, it seems great so far. You just have to edit agro ranges on some areas to keep huge trains from happening (Vexthal is really bad with the standard agro range).
To keep in line with this post, would it be possible to write a new section of source that evaluates doors separately so that they aren't seen through?