Can you be more concrete? Here's what I'm imagining you're saying: first you take a month's paycheck out of the bank in yuan, in cash; then you walk down the street to a jeweler's shop that will exchange your yuan in cash for US$100 bills; then you send a WeChat message to a guy who sells Bitcoin, and the next day you take a taxi with your US$100 bills to a cafe, where he transfers you the Bitcoin and you give him the US$100 bills. Is that what you mean?

I'm wondering if somebody who spends all of their highly-controlled digital yuan in cash every month, and not on anything detectable, will draw suspicion.