I was recently having a discussion with @ajpri about this. He inspired me to start doing this with my DH. I have recently updated one of my biggest offenders.
@ajpri has done the ST power sensor.
This is why I suspect they have not created a v3 hub. I don’t think there are enough people (yet) for them to make money off a v3 hub if 90% of us don’t upgrade because we don’t have a migration tool. Yes, I think a lot upgraded to v2, without a compelling reason to upgrade to v3, I suspect we will all stay with v3 without a migration tool.