Anybody have a Wingrack with a PLASTIC monokey plate?

[Fuzzy]

I recently took delivery of a Givi Wingrack 2 which came with an aluminium "m3" monokey plate. The plate's a bit worse for wear and as I have another "m3" plate (currently fitted to a monorack) I thought I'd use that - however that one is made of plastic/nylon or similar. They are totally identical apart from the material they are made from.

I emailed Givi about it and have not had a response. Does anybody know why there is an aluminium and a plastic model? I wonder if it's safe to use the plastic one with the Wingrack - anybody got a plastic one fitted?