First-time UHK 80 usability issues

[mondalaci]

The https://www.youtube.com/watch?v=2P1AZCtm_UY review highlights some usability issues that should be addressed:

1. At 2:49, the user wakes up the right half of the UHK 80 accidentally. Maybe it'd be better to explicitly request the J+L keys without pressing any other keys.
2. It's not communicated to the user that the left half is discharged or in sleep mode, so he doesn't understand why it's not working. The display should indicate to the user that the left half may be discharged or asleep and can be awakened by pressing S+F together.
3. At 3:08, the display shows "USB: remote wakeup request failed: -1" messages, which are very confusing from a user standpoint and should not be displayed at this point.