The telemetry stream rates are controlled by the SR* parameters (50Hz max, it will warn you if you try to enter over 10Hz). I didn’t mention this before because there is an issue here, where the stream rates in our system are currently governed by mavproxy running on the raspberry pi. To change them, you will need to enter the command ‘set streamrate 50’ command in the mavproxy console running on the raspberry pi.
Regarding the larger log files, we can put an issue report in QGroundControl. Is there a particular threshold in filesize where it fails?
The motor output channel definitions can be seen here.