Something about my use of chrome.hid.send
seems to be leaving the bus in a bad state. I consistently can NOT get my second usage of the API call to work. Sometime
The issue is that Windows requires buffers to be the full report size expected by the device. I have filed a bug against Chromium to track adding a workaround or at least a better error message to pinpoint the problem.
In general you can get more detailed error messages from the chrome.hid API by enabling verbose logging with the --enable-logging --v=1
command line options. Full documentation of Chrome logging is here.