I dunno, I think the ultimate hacker would sometimes reach over to the other side with her left or right hand. Split keyboards seem like kind of a walled garden to me.
Used to think that until I used a Ergo 4000 and within a week once the swearing stopped I realised I was never reaching over the river in the middle.
It also completely solved all the pain I was having in my arms and wrists so while I miss the key feel of my mechanical keyboard a little bit I wouldn't go back.
It's not as bad as it seems to make the switch. I switched from a regular QWERTY layout to an ErgoDox. It's split, and it's a columnar keyboard whereas standard keyboards are staggered like a typewriter.
It took me a week or two be able to touch type comfortably, and now I can switch back and forth without too much trouble.
It also completely solved all the pain I was having in my arms and wrists so while I miss the key feel of my mechanical keyboard a little bit I wouldn't go back.
Something like this might be interesting though.