I'm not really stuck on the idea of a 12 column keyboard. 11 columns can be done, but you need to let go of some keys.
Id like the luxury of keeping all those keys, but if the tradeoff is that they have to be 0.5 or 0.75 wide keys, I simply won't use those.
And that tiny caps lock key snuggled up against the "A" key, I can guarantee I'll be prying it out of the keyboard when I get tired of accidently hitting it.
I've been using a 40% sized keyboard for a bit, and I've given up so many useless keys, I don't even miss them.
I'm in the middle of wiring up a custom 30% 35 key keyboard right now, you'd be surprised how much functionality you can cram into so few keys when you get creative with the function layers. https://youtu.be/D8yM-IVX8Fo
I spent some time analyzing my typing habits, and I learned that I never once touch the following keys:
- Right shift
- Right Ctrl and Alt
- Left Windows key (I only ever use Right-win + L/K/P)
- Menu (next to the Right Win key)
I also learned that I rarely use caps lock, and I never touch the left half of the space bar.
I totally respect your desire to have every key you need on it, but I'd encourage you to check out the world of 40% and 60% mechanical keyboards. I think you'd be impressed at how easily you can get used to a new layout.