Sticky Alt and Ctrl makes sense for you given the fingernail activation, but won't that make copy/paste a pain in the ass?
I don't see how sticky ctrl would make copy & paste cumbersome.
Sticky and non-sticky copy & paste are the same because Ctrl and the letters 'C' 'V' are on opposite hands.
Sticky is needed when the letter to be modified is on the same hand as the Ctrl key.
e.g. underline selected text in Word:
Ctrl+U
where Ctrl and the letter 'U' are both on the right index finger, making simultaneous key press difficult.
Holding left mouse button key with fingernail for a long time while selecting text might be strenuous.
And are your layer keys sticky? I've always used temporary activated layers, but that may be what makes me less fond of layers.
You're making me rethink layer keys (that's a good thing).
I added an 'Alpha' layer key to the layout. A spreadsheet of the updated layout is attached.
They are 2-mode-layer keys. Here is how it works:
There is always exactly one one locked layer, the other layers are unlocked.
The locked layer is active when no layer key is being held down.
When a layer key is pressed, its layer becomes temporally activate.
When the layer key is released,
if no other key was pressed, the layer becomes locked
else another key was pressed, and the locked layer becomes active again.
Table of layer usage:
LAYERS
TASK ALPHA SYM Fn UNLOCKED LAYERS TEMPORARILY USED FOR
typing locked insert symbol, move cursor
data entry locked insert letter, move cursor
navigation locked insert letter or symbol
This 2-mode-layer key is something I invented, and it has not been tried as far as I know.
Please let me know if you see a flaw, or know of a similar implementation.