Yep, there it is. I had missed that!
Ah, how interesting! A 3/16 id hose works out to be 4.8mm. Do you plan on running 4mm hose all the way to the low pressure side of the tap king or joining to 6mm hose as in the mrTbeer method? I wonder if a hose clip/clamp would get a 6mm id hose tight...