Audacity is built with WxWidgets, which is a cross-platform toolkit for making graphical applications that work on multiple platforms (Audacity supports Windows, macOS and Linux).
In WxWidgets, custom cursors are created as 32x32 bitmaps, and as far as I’m aware, there is not yet any way to scale this size within the application. Until WxWidgets provides a way to create custom cursors that can be scaled according to the display dpi, I think your options are:
- Reduce the display dpi for your monitor.
- See if Windows provides “display scaling options” in Settings that allow you to improve the appearance (I don’t use Windows, so you’ll need to test this yourself).
- Use a third party app to “magnify” Audacity (there may be some “accessibility” app that can do this).
- Add a second display to your computer with a lower dpi (dots per inch).
- Put up with it.
Final thought:
There’s an option in “Mouse Properties > Pointer Options” to “Show location of pointer when I press the CTRL key”. I don’t know if that works when using one of Audacity’s custom cursors, but perhaps worth a try.