Its probably better to use some form of server-side rendering. You can put it in an iframe, but that's bad for accessibility. You can put it in a regular frame, but that element is deprecated. You could also make a small script that adds the contents of the file into a div
Considering its the url used in the microsoft store, I'd assume it is. The name servers are also azure urls.
Eh, whatever it is, if anything, isn't really affecting me too bad. The test is interesting, but the lack of nuance in it (only true, true at certain times, or never true) makes it hard to answer.
I have a deskjet 990 (i think) working fine in the attic. Just plug in the cable and it works.