"How does the system account for high-performing employees that are too busy working to prepare presentations for promotion committees? Is there no such thing as an unsolicited promotion based on performance under this system?"
I think maybe "high-performing employee", in this system, is simply defined at least in part as "one who prepares excellent presentations for promotion committees."
In any system based on individual inequality a high-performing employee is whoever is appreciated by the central authority. If you actually want to award performance you need collective inequality. That is, you need differences between successful and unsuccessful projects rather than between employees deemed successful or unsuccessful in those projects.
I think maybe "high-performing employee", in this system, is simply defined at least in part as "one who prepares excellent presentations for promotion committees."