I've been playing with Dvorak and was thinking about how it is fine once the OS loads but until the n the computer is pretty much in QWERTY mode.
That's an interesting thought. But aside from the fact that mapping to Dvorak in the OS is likely to be good enough for most of the people who use Dvorak, there is the additional problem that converting QWERTY to Dvorak doesn't convert QWERTZ to Dvorak, or AZERTY to Dvorak.
In fact, you've just pointed out a serious design flaw in the PC platform. In order for German and French and other keyboards to work
as people would expect, instead of sending scan codes, keyboards should be sending ASCII to the computer, with the keyboard arrangement
hardcoded inside the keyboard itself.
However, the technology to do that, and yet
also allow switching keyboard layouts, wasn't there at a reasonable price back in 1981. In fact, Unicode wasn't there in 1981, for that matter.