In-zone evac line seems broken / un-livelike

[John Adams]

That's one impressive disclaimer. Welcome, btw.

I can verify, Succor (1567) and Lesser Succor (2183) do warp you (sometimes into solid walls thanks to bad coords), and do not wipe aggro or zone you (which in itself wipes aggro). Might take a look through spell_effects.cpp, search for "succor" around line 261:

			case SE_Succor:
			{
				float x, y, z, heading;
				const char *target_zone;

				x = spell.base[1];
				y = spell.base[0];
				z = spell.base[2];
				heading = spell.base[3];
								
				if(!strcmp(spell.teleport_zone, "same"))
				{
					target_zone = 0;
				}
				else
				{
					target_zone = spell.teleport_zone;
				}

If you can read the code, that might show you where the zoning does not occur and why. My own disclaimer, I know little about C++ right now, except how to follow flow. I'm more a database guy, but this is where I'd start investigating. Download the source, and simply Search *.cpp, *.h files for key words. Barbaric, I know, but it works for me.