Early this year I started using Logitech K810 keyboard on Mac and, more recently purchased an additional keyboard that is popular among picky programmers, HHKB Professional 2 (US key, black). As is often the case for non-Apple-native keyboards on Mac OSX, I needed to modify some key bindings of these two keyboards to enjoy a comfortable coding experience on the Mac desktop environment.
Below is the custom Karabiner settings which I have put in
~/Library/Application\ Support/Karabiner/private.xml. The key bindings for Logitech K810 and HHKB Pro2 do not interfere with each other thanks to the device_only option, so it is okay to enable the options for the both keyboards at the same time. The custom key mappings for K810, if enabled, take effect only while K810 is being used and vice versa.
Combined with these tweaks, my favorite Karabiner key bindings are as follows:
I can't live a day without these key mappings.