What about an in between PS/2 or USB dongle type device that allows switching from either keyboard to either character mapping? E.g. if I have a qwerty keyboard, I set the dongle to be "from-qwerty to-dvorak".

This way I could switch say a das keyboard without modification to the keyboard itself.

Edit: just found this - http://www.keyghost.com/qido/

I see areas of improvement for a device like that.

I think I like that idea a lot more than what I currently was planning and it's more something close to what I've done in the past and something that could benefit others more easily too. The biggest improvement would probably be get rid of the $150 price tag.

Not sure how you plan on improving on the Ergodox infinity, which seems to meet every one of your specifications except the price. And as someone who has built my own ergonomic dvorak keyboard from scratch I can tell you that it will end up costing way more than you think, on par with the ergodox. Although also as someone who built my own I respect your will to try. See http://thume.ca/2014/09/08/creating-a-keyboard-1-hardware

I think you're probably right. I wouldn't be able to improve on the infinity or axios. My only problem is I need more tenting than either offer. I currently use a freestyle2 with near 90 degree tent on both sides. https://www.kinesis-ergo.com/shop/freestyle2-for-pc-us/

I suppose an adapter/plate to tent one of those existing keyboards would be a lot easier.

I can suggest you to use typing study to learn to touch type on dvorak

http://www.typingstudy.com

I can touch type in dvorak no problem (have been for 13 years) but some things don't recognize the system keyboard layout in which I have to type with QWERTY. After not using QWERTY for so long I can no longer touch type with it so I am hoping there's a hardware solution that would be independent of the OS.