I don't really understand where you are coming from?
You have a product, that's the main item, and you wish to create an accessory that attaches to this, but won't have the potential to cause any damage.
I feel you should select the best material for the job it needs to perform, be that metal, plastic, glass, wood, whatever.
I don't select the material using the "Cool, Hip, Trendy" scale of calculation.
I also don't have mental problems in understanding that in some instances, making an item from a nice grade of plastic, with a nice quality finish may be a better material selection to perform the task than aluminium.
As I said, Some people have a problem with this, and for historic reasons cannot help but think: Plastic = Rubbish.
I just don't agree with this sweeping mentality. Every material has it's place, and it's own strengths and weaknesses.