Yeah the 9V / 12V thing worried me to, but Autocom been using that combo for years and so it must be ok. I was not keen about splicing into wires so mine plugs in to the Optimate lead direct to the battery. This means that the unit is powered all the time it is plugged in, but Autocom informed me that this would not harm the unit - the only thing they wanted to point out was it could drain the battery over time. This method worked well for 16 day tour last year, so not a big issue while the bike is in use. If the bike is not being used, unplug the Autocom and plug in the Optimate, job done.
