Perhaps this is common knowledge but just in case…
Today I discovered that key chording with 3 key sequences works in ST. 4 key sequences also works, and presumably beyond, but 4 is already overkill IMO. e.g.
{"keys": ["ctrl+k", "ctrl+j", "ctrl+v"], "command": "transpose"},
{"keys": ["ctrl+k", "ctrl+l", "ctrl+d", "ctrl+f"], "command": "transpose"},
This is actually v. useful. For example I use 'V' for various paste operations (inc. some plugins) and had run out of key sequences used with that letter despite the fact that I already use Ctrl+T as a second key chording letter, e.g. {"keys": ["ctrl+t", "ctrl+l"], "command": "select_text_on_line"} (transpose moved to "ctrl+t", "ctrl+t"). With the extra possibilities of 3 chord bindings I have been able to have all my pasting done with the letter 'V'.
Users may also find it useful to know that a modifier combination is not necessary after the 1st sequence in a chord, e.g. {"keys": ["ctrl+t", "l"], "command": "select_text_on_line"} uses no modifier with the 'L'.
Hope this is all of interest.