Yes I know. And I have tried that. Loading a 17MB xml file was not an easy task.
First up the XML document tried to show it, which hogged the machine for quite a while.
I couldn't find the option for not autodetecting the content type, but I guess I havent looked hard enough.
Next I tried pasting the same contents, but with some other text at the top, so to not invoke the XML view, and it hogged my machine again. This of course is not possible for real tests.
So a third approach would be nice, hopefully with a bit more speed.