It is partially possible with Karabiner Elements. The part that's possible is you need a minimum hold delay before __f__ turns into __Shift__, but otherwise it

It is partially possible with Karabiner Elements. The part that's possible is you need a minimum hold delay before __f__ turns into __Shift__, but otherwise it works without breaking your typing The other part of no-delay without breaking your typing style should also be possible in the software, but don't know of a great solution there