EXT Clock CX mode is a new mode that does the following:

MIDI Clock Only (CX), for syncing to devices that do not produce MIDI Start messages. Incoming MIDI Clock messages determine the tempo; MIDI Start, Stop, Continue & SPP messages are ignored. Otherwise the units behaves as if it is internal sync mode for Play/Record/Overdub from footswitch. If not receiving MIDI Clock, the EXT.CLOCK LED will flash and the unit will not Play, Record or Overdub. An active Play/Record/Overdub operation will continue at the last external tempo if MIDI Clock is lost.

We need to update the manual to include this new EXT Clock mode.