What does one do when your mouse freezes?
This is a response to a reply by "MrHoffman":
If your mouse freezes, you cannot use the keyboard as a mouse.
Choose Apple menu > System Settings, click Accessibility in the sidebar,
then click Pointer Control. (You may need to scroll down.)
Turn Mouse Keys on or off.
Note: When Mouse Keys is on, you can’t use the keyboard or numeric keypad to enter text.
It's really hard to "click Pointer Control" when your pointing device is non-functional.
In other words, Apple needs to accommodate the possibility that a device will fail, beit a hardware or software failure.
P.S. I haven't had an issue with the mouse for a while. Then again, I bypassed both of my USB switches and plugged the mouse directly into a port on the back of the computer. (The issue seems to arise without regard to which I'm using. USB disks and keyboards work fine -- it's just the mice. So, the USB driver is working, but the generic mouse driver is not. Or maybe the mouse driver doesn't like working with a USB switch driver, but I'm starting to get out past my knowledge of how UNIX-like (netBSD/Linux/NeXT/System5 UNIX,etc.) drivers work in a USB world.)
iMac 27″ 5K