Slightly on a tangent, but I recently did
a fair bit of research into keyboards primarily, but also mice. I was previously using a wired Corsair Strafe gaming keyboard and a wired Corsair M65 mouse.
I tried out a few different keyboards and ended up with the Logitech MX Keys. The reason I mention this is a function I don't actually use but which seems pertinent to your requirements - it has dedicated buttons for switching between control of 3 different devices.
Separately I tried out a few mice, and settled on the Logitech Master mouse - mine is an older model that Logitech appear to have licenced to a large online retailer which I picked up for £30 in a sale, but it seems excellent - when I switch to other mice I particularly miss its unusual extremely fast scrolling vertical scrolling function, and the side-scrolling wheel which I've reallocated to volume control. I also find its larger size much more comfortable in hand, but that's very specific to the user, so not of much help in your search.
I'd definitely put both the keyboard and the mouse on your list to look into in more detail.