Does this happen with all samplesets or just some (and which ones)?
Do you hear the same delay if you MIDI-learn a manual keyboard to play the same pedal division? If the manual is attacking faster than the the pedalboard on the exact same pipe samples, the difference might be that the CM pedalboard doesn't send MIDI velocity, and your manuals do, or a MIDI connectivity problem.
Many samplesets have velocity sensitive attack speed, so a default MIDI velocity from the pedals can cause a slow attack (initial transient before steady speech) -- maybe even a gulp sound. If that's the situation, it's possible in HW to adjust the attack velocity range (but someone else will have to remind me how...).
Other possible causes: MIDI cable or USB port from pedalboard to computer needs to be changed, daisy-chaining MIDI from pedals through one or more keyboards, not having a powered USB hub to group MIDI cables together, or not using a good MIDI hub like a MOTU Express 128 if needed. There are MIDI hardware suggestions in the HW user guide near the beginning of the book.