Anyone else notice how poorly Yubi conceals his cipher?

I'm watching "Gold Mine" again and I'm noticing that in those first minutes between "Montana" and Yubi, Yubi's cipher is in PLAIN SIGHT. "Montana" of course is Trask--who is also wearing a cipher. Yet is wise enough to keep his concealed until he chooses to reveal his identity to Yubi.

But Yubi, just by allowing his cipher to be uncovered, has, essentially, advertised his identity--or at least his point of origin--to anyone who might recognize the device.

Anyone care to speculate if Trask knew from just seeing the cipher in the woods who Yubi was?