Power Module / 3D Printer Module /Linear Module

Hi @Blockmodule,
thanks so much for sharing the innards of the modules! One thing I cannot see from the pictures clearly: The nuts that ride along the lead screw have been made of plastic in the old modules (see e.g. here: Excessive play in x-axis linear module bracket - #9 by sdj544). Are they still plastic? Or did they finally go for metal nuts?
Cheers
Hauke