The immobiliser is standard on the bike (or so I believe). The alarm is the plug-in and not Thatcham approved (so why bother if insurers don't recognise it?). I did hear the same story from my dealer regarding BMW not wanting to pay the cost of approval.
As alarms go, it isn't great, and if it hadn't have been already on the bike when I bought it, I wouldn't have bothered. For example, by design, it deactivates after a few days to conserve battery. Sounds naff as well.