I figure the last group to get the updates would be marine installations (and possibly aviation ones). If it is 4 batches, you would have likely a smaller group for first round roll out in case there is an issue. Then dealers and a few "power users" then the bulk of the customer base and finally marine installations and others that would be in the low tolerance for dealing with unknown issues that could creep up. That is just speculation on my part but seems to be a reasonable rollout where it is not about mitigating the volume of updates but limiting the scope to manageable numbers in the start in the event things need to be rolled back for unforeseen issues and then getting most people, with the trailing group being those often times offline systems that would be near impossible to fix in the field due to intermittent connectivity issues.