brucefromvancouver wrote:
Am I right that Bootcamp lets me run Windows on a Mac, but it doesn't let me run Windows apps like this mouse/keyboard utility while using MacOS?
Correct. It essentially turns your Mac computer into a Windows computer by installing a copy of Windows on part of the disk. You wouldn't be able to access macOS while using it, so I'm afraid that's not a solution if you need to use Apple apps (and yes, a cheap Windows machine would probably work better, as Boot Camp is really designed to allow the use of both macOS and Windows).
While macOS doesn't have a SteadyMouse equivalent, it does have Mouse Keys, which allows the use of the keys to move the mouse around the screen. You may want to try it out- see here for more information - Control the pointer using Mouse Keys on Mac - Apple Support
If you'd like to submit feedback to Apple regarding the addition of a mouse-steadying software, you can do so here - Product Feedback - Apple
I'm sorry I couldn't be of more help!