USB VGA sounds kind of like a hoax. Is it? To some extent, yes it is.
20160104/https://en.wikipedia.org/wiki/Free_and_open-source_graphics_device_driver
20160104/https://en.wikipedia.org/wiki/DisplayLink
The current solutions rely on video compression algorithms. And, as you know with any data compression algorithm, there is always the possibility of a worse-case that cannot be compressed at all. What happens when a video signal relies on a channel that cannot send enough video bandwidth except when the signal is compressed? What happens when an uncompressed signal must travel to the destination in time? Nothing, because it can’t reach its destination in time.
Interesting link, just saving it here for reference.
20160104/https://www.fsf.org/news/fsf-and-debian-join-forces-to-help-free-software-users-find-the-hardware-they-need