Is there a problem combining key-chord-mode with evil? After some puzzlement I discovered that key-chord mode only works (this may have changed recently) when activated (by M-x) in insert mode. Leaving insert mode disables key-chord mode.
Recall that for nearly any package what keys trigger what action is resolved by looking it up in the active keymap, falling back to less specific ones if the key couldn't be looked up.
key-chord.el sets up a custom input method which triggers for self-inserting keys while Evil sets up a keymap with high specificity for every known state (we don't call them modes because the word is heavily used in Emacs already), with insert state and Emacs state being the only ones that let self-inserting keys pass through. Therefore the described
The big exception here are packages that use
post-command-hook to work around this, be it for faking or dropping user input. One of those is evil-escape, it works in any Evil state for that reason.