EDL V2, EDL V3, and USB-Link 3 will all work, for now. Yes, it is subscription based. It is per machine, or by fleet. I do not know if there is an option for "ALL". I'm just a tech, so the particulars of what is available for customers would not be something I have access to. I know as of right now, the Pro Service is "online" only. I'm guessing that will change as it evolves. So, if there is not an internet connection, it will not work. I would imagine an offline version will be coming because our Service Center has an offline version, which is what I use.