Alex is getting a supplier to make up some "Thermobore" for hot wfp systems. It will be 8mm ID, and rated to 90 deg C,.. and I'm sure he mentioned early on a reflective insulating layer in the hose to minimise heat loss before it gets to the brush head, hopefully this feature made its way into the finished product?
I'm sure Alex will give us more info when its ready for sale tho.