Your dimensions sound fine for most speakers at least for the starting point of set up. To oversimplify the effects of toe in, the two extremes of toe in are having the axis pointing at your head - you should get a very focused sound stage mostly between your speakers. Listening off axis, up to where they are pointed straight ahead, will give you a wider sense of sound stage. This comes from side wall and to a much lesser amount ceiling reflections blending with the off axis sounds from your speakers. You will lose however some of that focus. Also, some speakers are too hot when heard on axis and folks find that by firing them straight ahead reduces that HF energy. This is probably why many folks find that listening to speakers with the on axis sounds crossing behind their listening seat creating an angle of about 10 to 15 degrees creates a good blend of sound linearity and room reflections.
FWIW KEF knows the effect of their speakers dispersion pattern and by their suggestion that they fire straight ahead I assume that the speakers might be a bit hot on axis.
Sorry I can't help you with specifics about your speakers, but, frankly I don't think it matters that much. Understanding speaker design and room acoustics is much more important to getting a good set up. Books are written about this! :-)
