Add a user setting toggle that synchronizes switching between peripherals
(i.e the user switches to device 3 on their keyboard, and the mouse follows suit by also switching to device 3 without additional user input)

Please, everyone wants this feature, and I can't imagine it being that hard to implement. I'll even draft up an acceptance criteria:

Given the global easy-switch setting is enabled
When the user presses the easy-switch key/button
Then all easy-switch compatible devices should switch to the same device that the user is switching to