Still not sure if I understand it, sorry
Does a mapper have to specify that a normal/specular/etc. map should be used, or will the engine automatically load the respective maps if they exist?
If it's the former, then it doesn't matter so much, because the mapper will not load the default values if they don't fit.
If it's the latter I'd suggest you at least switch off the glow
So in that sense, I guess I have answered my question myself. Or else you would be getting lots of complaints that everything is glowing bright white...
Still, maybe a default specular map of 0.5 or even less would be more appropriate. That way you can use the default for pretty much anything unless a specific specular map exists.
Unfortunately my graphics card doesn't seem to support these kinds of effects, otherwise I'd experiment a little myself.
Voller