If anyone comes across one of these and can take a photo of the internals, I'd love to see how it is constructed. For now I'll make a version with point-to-point wiring, I'll upload more pictures once it's done.
Jared
I can't recall seeing that on the cal certificate of a 4284A which I had calibrated by Keysight. Not 100% sure. I managed to get a free option 006 (support for 4 m cables) from them, which might be very useful for a possible job I have coming up.