I will verify with the manufacturer but I believe this is the default value based on when I exclude the device it has a 700ms delay and when I re-include it the value of the parameter is 1.
My guess is that the storage space for that parameter already has data in it. When you do the firmware upgrade the storage space is not written over (not sure if this should be part of the z-wave firmware process or not). When I have programmed firmware I have had to write the data upon first boot after a firmware update. Otherwise it retains whatever information was there before.
Another thing that makes me think this is that I queried the parameter after a firmware update and it returned a value of 254 or something really strange.