Brake disc options for Delite GX Rohloff (2018 model)

[djsb]

Hi,
I have a Delite GX Rohloff (2018 model). It is fitted with Shimano BR-M8000 brake calipers (Front: Shimano Deore 180 mm 6-hole Rear: Rohloff 180 mm (4-hole)). I am fitting a new Shimano SM-RT-56M 6 hole disc on the front wheel. However, I'm wondering if there is any alternative to fitting a 4 hole Rohloff 180mm on the rear wheel. Thanks.

 

[JVBulman]

Rohloff only makes one 4-bolt 180mm rotor in the 1.8mm thickness. Last time I went looking, there were a handful after-market options floating around, but all seem to just be different aesthetically rather than offering better performance or any additional features.