would like some continual feedback/watermark on the screen indicating which device I'm connected to. Sometimes I start typing, and I'm not on the device I intended.

Use case: Worse still is if I start typing incorrectly on a device that when I hit enter it sends a message to the wrong audience in some communication app on the wrong device. While true, the fact that I'm not seeing my typing in the device I thought I was on should be an indicator.... that is usually realized after typing is done. There should be an onscreen indicator I can glance at and then feel confident to start typing.