The hardest part of converting EQ zones is wrestling with the various file formats. It looks like WLD is a well understood format, but none of the existing work on EQG files gives me any texture information (or I haven't found it yet, OpenEQ source might be handy here but all the links are broken.)
This loads the .map files the servers read so some of the geometry is omitted, but it would be easy to tell azone to output mapfiles with full geometry if one wanted to.
http://dungeoncrawl.us.to/eq/mapvis/?zone=crushbone
For WLD zones those json map files could easily include textures and UV's. The only thing you lose is the EQ spatial database of choice. Most modern engines use an octree scene graph with frustum culling by default, so just breaking the zone geometry into reasonably sized chunks should be serviceable.
I have some progress on a zone converter that borrows heavily from azone2. It can output the zone model and all the placeable objects as individual model files, but textures are hit and miss.