I am ashamed to say that this did not even enter my mind even though I long ago installed this add-on on my own machine to assist me in following where NVDA is focused.
I will also add that it is not perfect, but it's so darned good that it could serve as an example of how this can be done.
For myself, I probably wouldn't even need the actual highlight boxes if screen readers do what NVDA and this add-on do together, and that's make what's showing on the screen actually reflect what's got focus (or very near to it). Very often what's got focus can be pages ahead of what's showing on the screen. I understand that what's showing on the screen is utterly irrelevant to someone who's blind, but I assume, particularly in work contexts, that there is a lot of interaction between blind and sighted colleagues and this particular behavior leaves both sides of a "hey, take a look at this" situation in a suboptimal position.
Here is a test to find out whether your mission in life is complete. If you’re alive, it isn’t.
~ Lauren Bacall