I don't know if you guys have the same situation, but I have found that my Cemanis are really flighty and they are also just as fast...but thankfully also "chicken stupid" as usual...
out in the open, if they are paying attention to you, which they almost always are, you will never get closer than 10 feet from them.
I have to use two sticks, like the guy at the airport who parks jets.
It takes practice but by widely flanking them (walking around them) and waiving the sticks in each hand I can successfully "herd" them to where I want them to go about 90% of the time...
Also on a side note:
I have noticed that they can see in near darkness, unlike all my other chicken breeds...
All my other birds will be well and away up in the coop as the sun sets... but not my cemani...
They are still out in the closed run pecking and scratching away in the dark.
Clearly looking at me like "What's wrong with you? ignorant human...All chickens can see in the dark?"
They only go up into the coop an hour or so after total darkness falls.
I suppose both of these traits are because they are recently from the Jungle...
but that is just conjecture on my part.
Have you guys noticed this as well?