The reason for why I've not tried this is probably mainly because it would scramble all keyboard shortcuts. Shortcuts are designed for qwerty (a shortcut that you can't perform with your left hand anymore is a huge loss) and many combinations are a huge part of the workflow of many applications. I found this to be a complete showstopper.
I think there are ways to automatically switch to qwerty when ctrl/shift/alt was pressed and maybe I didn't research it enough but it felt like a cludge and I wan't something that is platform independent and easy to enable on any machine.