Stamp Vertex Objects

I've been trying to make a XPack with stamp vertex objects without success.

Objects whit this shader always face to the viewer, and this is particullary useful for crowd or trees, as they look like 3d objects, though they are made using only one face (or two triangles).

Vertex coordinates are unique, but there is an extra channel in texture coordinates to show the "projection" of the texture from the unique vertex point. This is a sample of a single file:!tA9WRSSC!nNYU6RLfTQLglPZoBhv9iHyGg7Geb7zjfrohbSUKKy8

3ds format doesn't support multiple texture coordinates channels, so I tried to use DAE, but when I export from 3dsimed (using the last Collada exporter), BTB's XPacker can't read the resulting DAE file. In fact, DAE files exported from 3dsimed, can be re-imported to 3dsimed, and texture channels remain almost the same (U coordinates are exactly the same and there's a minimum change in the sixth decimal of V coordinate), but Vertex Alpha changes to 255 making the object invisible until is changed to a different value.

Having the chance to add these kind of files to XPacker would allow us to make XPacks with crowds, trees, plants, rocks, poles and similar objects saving lots of polygons.

Any idea?
I'm not familiar with DAE files but XPacker is probably coded to look for a very specific pattern, which doesn't allow for multiple texture channels. I think it was meant to take files exported from tomato sketchup, which as far as I'm aware only supports diffuse maps.

In XPacker you go to Materials, and change the Shader property to, say, Diffuse and Bump and you'll get one or two extra tabs below. The extra textures are mapped relative to the diffuse map, so scale 1,1 and offset 0,0 means it lines up perfectly with the diffuse map. If the scale becomes 2,2, for every diffuse texture you get two bump textures. The default road uses high values like 6.8,5.2 to give a very fine set of bumps.
I know current Xpacker is quite limited in shader definitions, but in fact until rFactor2 there were no need to make a much more sophisticated Xpacker. But stamp vertex objects can be defined using only two channels, as bump and specular use to share texture coordinates with the main channel, and then there's only another channel to keep, and even the Vertex Alpha can be added to the gmt file when exporting from BTB.

This is more a suggestion for next versions, as the benefit of using Stamp Vertex Objects is great. Now, the only way to use it is through 3dmax, but there's a lot of people making tracks with BTB, and this could be a good improvement.