Thanks for this, Dan. I only needed an indeterminant progress bar for Mirror Mirror Macro, so I made a lightweight variant that conforms to that macro's color scheme.
One thing that concerns me is the size of the Keyboard Maestro macro file (plist and sync). In Why Is the Keyboard Maestro Macro Editor Slow & Laggy?, Peter wrote:
The editor is designed for a relatively small set of macros (<1000), a relatively small macro file (<2MB), and relatively small macros (<20 actions). This is the typical usage. It is not designed to scale arbitrarily to unlimited size, any more than Notes is designed to write your next novel in.
When I added this macro group (which I realize can be pared down quite a bit after you learn how to use the progress bar), my Keyboard Maestro file grew to 3.4-MB from 1.1-MB.
I'm not sure how important a <2-MB Keyboard Maestro file is, but I'm afraid to find out. 