I think the most likely way to make it work with A:M's use of decals is to make it a grayscale map, like other non-color maps.
White = full glow. Whatever is the surface color here will glow in that color.
Black = zero glow
Reach and Intensity are currently set in the Chor because Glow is really a post effect. It's done once to the entire rendered frame. The glow effect would have to be rewritten to get it to treat different decals differently.