So, I decided to share my keyboard position/layout I use in 2 years. And strangely I never see somebody use it like that. I hope it will be interesting/useful for some users.
Main problem for me was a little room on a desk to place a keyboard. I searched for various little keyboards, usually it is “gamer keyboards”, but none was 100% satisfactory. Still I had a second keyboard and some space in left from a tablet so I arrive to the next conclusion: why I need to place a keyboard horizontally?
My keyboard is 90° turning, and placed left from tablet. Still it is really comfortable to me reach any keys except of numpad. In 90% of workflow my hand just stay at one position and may cover about 40 keys, and it is less stretchy to move hand forth and back by 5 - 7cm to reach far keys than in usual horizontal keyboard position you need move a hand from right and left like on piano. And it is wonderful how vertical lines of keys perfectly fit for hand positioning/movement. Start position is “3”, “E”, “F”, “C”, “LAlt” keys for little, ring, middle, index and thumb fingers correspondingly. During work my thumb finger cover Ctrl, Win, Shift, CapsLock, Z, A,Q keys and other fingers cover: little finger is 1-6, ring is W-Y, middle is S-H, index is X-N and Alt, Space.
Of course, for this setup I was forced to remap all keys to fit my needs. Additionally I use AutoHotkey app to remap Windows and CapsLock keys.
Other plus of this layout is compactness. Vertical placement frees valuable space near tablet.
Only single disadvantage I see – you need flat or low angled keyboard to prevent hand to turn in, or it may be used some support to up the right edge. Also for left-handed users it my be different.