Octopus have emailed me offering to book (with specific dates and time slots) SMETS2 meters install. I have SMETS1 "Secure" meters and they work fine. Should I accept the offer to upgrade to SMETS2? From what I read, SMETS2 meters are fully portable between providers, where SMETS1 meters are limited to what each provider may support (i.e. I get complete freedom to move away from Octopus if I want to by upgrading to SMETS2). Is there any downside to upgrading? I don't have PV or a battery.