there is indeed some testing required -- by QHY. I'ts an issue of their SDK.
With the latest sources (QHY SDK 6.0.5) and my QHY163M the regulation stops after a while and the PWM value get stuck.
I rebuilt the driver with SDK 6.0.1. (had to comment out a new feature). Now it works, but its unstable: the PWM value jumps between a few percent and 90%. Because at least the 163's have a lot of power supply induced noise that's no solution.
I'll test which version is stable and send a report.