Agreed! Mastering complexity is fun! But there is of course also allot of fun to be had with the challenge of making a macro as simple as possible — In this way the quest for simplicity brings with it it's own sett of interesting complexities!
And on the note of exploring the subject of simplicity: I now today learned (through @Airy's OCR-timing macro) what might very well be the simplest way to display a looping oscillating progress bar while a macro is running: Through KMs very own Display Progress Action, of course! It have a handy little built in feature to oscillate when set to a value below zero.
Display Oscillating Progress Bar While Macro is Running Macro (v11.0.1)
Display Oscillating Progress Bar While Macro is Running.kmmacros (1.8 KB)
However the discovery of this very simple way, of doing what I originally set out to do, will not halt my new challenge to learing how to use Subroutines to solve the same task. (I guess I am not the only one that spends time in the KM-editor, building macros, not only as a means to solve productive tasks, but also in the sole interest of learning this amazing application better, and having fun while doing so?)