May be we shoud ask Doug to give as some advice on that issue. I think that models should have at least two skins at a time, with properties to set up, one for diffusion, one for reflection map, but don't ask me how and is it possible, but example from shockwave shows that it is possible for all systems without need for gforce 980000+.
May be aproach on both systems are totaly different. In shockwave you can get model from max exporter and model don't have skins. Each model can have more mesh groups and each group has it's own shader that can be controled by properties. All those shaders are not environment shaders, and they are controling only those models who have that shader applied. It means that you can have a bunch of models using one shader for reflections and one for diffuse maps.
For me it is little strange that so powerful engine like 3DGS have problems with (for me basic) issue like reflection map.
In my country there are about 10% of computers that can use shaders, so thats means I will cut down my market 90% if I use shaders for reflections.

Dont get me wrong I think that 3DGS is great engine, but I can not belive that simple reflection map issue could not be solved easy vay.

For me the ideal solution should be to have property (skill) to simply apply (choose) reflection map to a model. But for that engine should be writen again, from start