...You got me, it's a tip of the hat to Heinlein. I've put in several homages to my favorite authors and at least one nod to a television show so far...but yep, that's Heinlein.
However, the reasons the character Ia gives for boot chevrons during Basic Training in the first book, A SOLDIER'S DUTY, are the actual reasons the DoI (Department of Innovations) uses. Boot chevrons (in my series) are a way to train every single soldier for potential leadership positions, and to test them to see if they should be given potential leadership positions. This evaluation continues throughout a soldier's career in the Terran Space Force, but by starting in Basic, it gives the DoI a baseline measurement by which to compare the rest of a soldier's career.
And remember, in the TUPSF, pay raises are not dependent upon elevation in rank (though elevations in rank can give an incremental boost), but are rather dependent far more strongly upon years served and the danger of each type of duty post...so keeping a soldier a Private Second Class for twenty years because they have demonstrated zero useful leadership skills from Basic onward is not nearly the "punishment" one would think it would be.
So while the actual two words of the terminology used is in honor of Heinlein, I've definitely made the reasons and purpose behind it entirely my own. It's like calling extra-tough soldiers in some far-flung, interstellar-traveling future "space marines." The actual definitions will vary from story to story, universe to universe, but the name is just too cool not to use.
And the Rule of Cool always gets the higher pay grade. ;-)
~The Author