The pictured layout is Topre Realforce 91U with rather randomly assigned key symbols/functions. I'd love to use it, but my Phantom has incorrectly split right Shift, and I haven't bothered to get a proper Japanese keyboard for the most part. Thus, I have only one-column gap between (QWERTY) G and H.
I prefer to avoid the punctuation keys in general, and put those symbols on a layer instead (that's why I got the idea with diamond arrows, because I don't like to use those keys while typing). That layout with large modifiers helps: I have a pair of easily accessible AltGraph keys.