I mentioned previously that I'm now using a Matias Ergo Pro. One of nice features of this keyboard is the split space bar with each half settable to different function, so I thought I'd tell you about my latest configuration with regard to thumb key usage.

For the last couple of weeks I have been trialling using Extend on the left Alt key, with the actual Alt function moved to CapsLock. I have also forced myself to get into the habit of using right thumb (I had been using the left) for space bar. This has freed up the left space bar to be an extra SHIFT key for the left thumb.

Here is my layout, letter keys are Mod-DH of course, but note positions of modifier keys:
http://www.keyboard-layout-editor.com/# … cada9c3f71

I am finding I actually really like Extend on the left thumb. It has to be said this is made slightly easier by the layout of the Ergo Pro, as its left-Alt is slightly further to the right than usual. The thumb mostly sits right over that key and is ready to spring into action faster even than when using CapsLock for Extend. Especially nice for backspace/delete I find. It did seem a bit strange having Alt in an unusual place at first, but I find it's not a heavily used key so hasn't caused significant disruption.

Switching Space from my left to my right thumb was a different story - this was much more difficult, as using my left thumb for space had become ingrained. I am over that hurdle now though. This also has some nice benefits combined with my new Extend location, as Enter is now done with both thumbs (Extend + Space).

AltGr is in the default position, but this configuration also makes it easy to access the AltGr second level (AltGr + Shift), as these can also be done with both thumbs. Not that I really use that feature much, but to some it could be useful.

The upshot of this is I now have four thumb keys, two for each thumb, which I am finding very pleasant indeed.

The obvious flaw in all this, is what about when I need to use a normal keyboard without the split space bar. In that case, I have come up with this which replicates as close as possible the modifier keys relative to the home position on a standard keyboard. Of course, for it to work, the Wide Mod is needed.

http://www.keyboard-layout-editor.com/# … d49372e0f3

The weirdest part I suppose is using AltGr for space, with the spacebar becoming Shift. But if you're used to using right thumb for space, this ought to feel natural fairly quickly I imagine. Even so, ideally I would get a small portable keyboard with a split spacebar for those occasions where I don't have access to my Ergo Pro.

Anyway, report over. I don't imagine there will be many takers for this as moving modifiers and Space around is probably too big a step for most. I suppose I am mainly just trying to sell to you how now nice things can be with a split space bar. Hopefully more split-space keyboard will start to appear.  But even without that, I think there is also a lot of merit to considering defining Extend on left Alt too!