M.Henderson

Automatic switching between Apple Watches has worked (mostly) since when I upgraded from the original to the Series 4. I now switch between series 4 and series 7 watches on a daily basis, which works at least 95% of the switches. The most significant flaw is that notifications for most installed apps that happen when a watch isn’t being worn trigger in the first 15 minutes of being subsequently worn. 

Isn’t the 20Gb/s interface called USB 3.2 Gen2x2 ?

One significant flaw in automatic switching is software updates; Apple assumes updates occur overnight when user is not wearing any Apple Watch. Since I am always wearing one of my watches to track sleeping with the AutoSleep app, Apple does not try to update the other watch, regardless of charging or not charging. To force an update, I have to either take off an Apple Watch and not switch to the other and then wait for update to occur, or go to the Watch app on my iPhone to force the update, or unlock the Apple Watch while charging and force update via the Settings/General/Software Update on the Watch.