(Attribute Node) Vertex Color for Selective Opacity

Hi,
I’ve been experimenting with vertex paint to accomplish a few things.
i see an example in the verge manual of assigning material attributes through the RGB value of vertex colors.

is this the right type of setup for changing the opacity of different parts of an object?….

every part i painted is either 1,0,0 or 0,1,0 or 0,0,1 etc…
it’s kiiind of working… but also dims the overall opacity in general.. and isn’t being precise or produce expected results…
(would i need to do a clamp or greater than or map range types of thing here if i wanted more DISTINCT , controllable areas BESIDES just absolute R,G or B?)

since bones are used in verge does that mean verge can access weight maps?

would that be an option for this type of scenario as well?
vertex groups?

thanks!