I don't think the stuff on the page you quoted is aimed at people other than auto-immunes with no residual insulin capability. We (auto-immunes) can, at least in theory, stabilize our BG over 250, though for me I would feel terrible and be looking for something to eat. In practice even for auto-immunes I think it is a dumb algorithm; my correction ratio goes up when I exceed 250, I have "sticky" highs, and, mathematically, the algorithm sucks; it's necessary to measure the half-time (half-life) of the decrease to get a number that is meaningful.
The simple assertion that you can manage DIA and correction factor at the same time is totally, utterly, bogus and wrong, wrong, wrong. (Unless you know how to do it; not the way they imply!)