It took about 24 hours but I got an email back from their technical support.
Apparently their datacenter is in Florida, so I'll have to forgive them for the initial unavailability, because it isn't like there's a giant storm rolling through the state or something....
I managed to get the PDF directly emailed to me in the end. It's a 30mb pdf but it is indeed the entire service manual.
Unfortunately the CO-V300 and the communications protocol is not discussed.
