I have this very faint recollection from my late elementary school days back in the end of 1980s of a very specific piece of MS-DOS software that claimed to do what was an incredible thing to an eighth-grader of the day.
The software was marketed with a claim that it would make an EGA graphics board able to emulate the 640x480, 16 color high-res mode of VGA. At our school, we had a computer classroom full of 80286 machines of the day, complete with EGA boards and monitors. I recall trying the software up once in one of those boxes, bringing with me a painting program on a floppy that I had carefully set up to run in VGA mode; the program, named "Dr. HALO" or something like that, was well suited for this testing because it had to be configured for a specific graphics board and would only run at all if the machine could support the chosen mode, not gracefully downgrading if the setup was not met.
To my awe, the painting program did indeed start up and run when the emulation software was active (the emulator deployed as a TSR program, as did a lot of MS-DOS utilities at that time). I had neither the time nor the knowledge to systematically test the performance or reliability aspects, so I can't say how good or usable the emulation would have been in productive use; back in the day it proved its point to me by just showing that such emulation was possible (or, at least, I was reasonably sure that it worked).
Now, decades later, I'd be very interested to find some references as to what was the name of that software, who the developer was, and how the VGA emulation worked. Alternatively, should such emulation not be possible, I'm also interested in that fact and why it is so; I was quite sure that I managed to run the painting program in VGA mode (we had a VGA machine at home, so I could tell the appearance of VGA graphics from EGA), but I do recognize that I was a thirteen-old kid, and it's been a long time.