Looking at this from the point of view of the treasury desk (I worked on the corporate desk, they set the rates), then it seems the risky scenario is the following.
If a 30% depreciation of USDCHY is in the works, that means I want way more yield for my long bond (doesn't mean I'm going to get it, but I sure do want it). It's hard to say how much Chinese buying supports the long treasury market, but I suspect we will find out.
Increase in 30YR treasury rates would be interesting (but no one ever listens to us bond guys).