VRayDecal mapping coordinates

[briareos_kerensky]

I'm trying to use VRayDecal to add placards around an airplane: things like "no step", "do not touch", "rescue", and so on. All these placards are grouped in one image for ease of changing colour, fonts, sizes.
If I apply an UVW Unwrap or UVW Mapping modifier to crop the image to fit a single placard onto a single VRayDecal, the VRayDecal turns into a standard mesh. The same happens if I use a Material modifier (to put the material into a Sub/Multi Object material).
I can use the Bitmap/VrayBitmap crop function, but that would mean duplicating the material for every single placard.

Is there a way to have apply mapping coordinates directly onto the VRayDecal, without having to act on the material and its maps?

[fixeighted]

You could make masks based on the original atlas's size, so masking out all but each single 'sign'.
Using one material for all the decals you can then use those those masks for each specific decal.
Hopefully that makes sense