Contacted him on @The Undying Nephalim's suggestion not too long ago. He said his audience was not into 0 A.D. but maybe he'll try it someday. It's been a few months now.
@smiley might know more.
In the mean time you might want to look at the in game chat commands there might be a way to check for a given nick and not display their messages. So you'll still receive them but they won't bother you.
You can use the same way than for carthage buildings. But it's not an overlay you need extra textures.
Do you have a diff of what you changed in model common?
Keep up the good work