I was actually really excited to see this project pop up, because I am on a tenkeyless keyboard and so I can't use the built-in mouse keys functionality. It's funny that so many of the accessibility features in Windows are really opinionated and can't have their keys rebound. Mode switching to HJKL-as-mouse is just a preference for me, but I could imagine there are types of mobility disabilities where repositioning your hands any time you want to emulate a mouse could be difficult and frustrating. What's the point in MS making great built in tools that can't be modified to your own use cases?