Any evidence (blockchain addresses) points to YiFu using the chips to mine for his/Avalon's personal gain.
*YiFu orders 30,000 chips*
"Hmmm, I sure could mine a lot of bitcoin with those chips. Yeah, let's do this. OK everyone; I want every 5th Avalon unit made for customers. The other 4 go to the mining farm."
*Answers phone*
"What? No, sorry, I haven't heard anything about the chips you ordered. There can be delays when you deal with a multi-billion dollar company that produces millions of chips everyday. Yes, I'll be sure to update you."
Oh yeah, email sent to Brent Davidson