How far to the side walls? Generally speaking, toe in/side wall reflections are not independent of each other regardless of speaker design except for panels and electrostats. The further from the side walls the less toe in......but its all room dependent (your room!) :-) I don't have KEF's but its pretty much the same for all of the box speakers I have used.
When I had my KEF Corellis, oh so long ago, I had them pointed slightly inward, as far from the walls as possible in my series of modest apartments. Depending on my mood I'd either have the grills on or off. The grills gave me slightly better orchestral tone. The absence of grills gave me a better image. In any event, buying the KEFS was revelatory in my audiophile development. An utterly different tonal world than what I'd been stuck with previously. Even hooked to my Kenwood Receivers.
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! :-)
When I had my KEF R5s, I had them toed in a few degrees and felt the imaging was better that way. I tried them pointed straight out, and toed in significantly, straight out the center image wasn't as focused as I wanted and toed in too far, the soundstage collapsed.
I never measured exact toe I settled on but it was maybe 5 degrees at most.
It seems the group agrees that a few degrees of toe-on sounds better. My 5’s are set about the same as yours, but I might have a few more degrees of toe-in. I’m doing it by ear, so I haven’t measured anything yet.