Regarding the 2nd Dye Slot in certain gear

[slayer20]

I am by no means a programmer but I think it's the 2 dye channels are tied to say, "Material A" and "Material B", and A/B aren't exactly "uniform" across all pieces of gear. So B may be tied to trimming on one piece, and on another it's tied to... hardly noticeable details like buttons. Then there are pieces that will have gradients (the level 100 GNB goat) that are separate materials and are also undyeable so you're stuck with them no matter what. It kinda feels like the issues the new dye channel set out to solve are still there in many regards, so... 3 dye channels when?

Unfortunately I feel like dye channels are unlikely to be changed because they might have the reason of "well some people might already like how the dye looks so we don't want to upset them".

I don't think this is the case. We have the means to look at the textures and materials used in game, and if I understand correctly, they do use single textures for gear pieces, but they are uniquely set up with mask layers to color the individual areas. I could be very wrong about this, but it seems like this is how they do it.

Edit:

I can say though that individual pieces of gear having multiple textures/materials for different parts on that gear would be insanely inefficient given the amount of gear in the game already.