I do hold out hope for the BatteryFlex idea, if only because it gives a future use to units withdrawn absurdly early, but I suspect it will probably have a similar germination time to the 769 project - it's similarly complex and being run by the same ROSCO, so similar contractors will probably be involved. As the 350/2s aren't going off-lease until the 730s arrive, which are also very likely to be delayed, it's probably going to be near enough 2025 before a BatteryFlex unit sees commercial operation. By that time, the next Northern franchise will be looming, if privatisation is even still on the agenda by that point.