For me, it didn’t prompt the upgrade when I went to the firmware page, but it did prompt for it when I went into the matter settings page.
I think Switchbot does slow rollouts, but if it’s not available for you yet you can just send them a message in the feedback page of the app and they’ll probably be able push the upgrade to you (I’ve done this a couple of times for previous matter releases).
Not local, but I’ve been using my withings scale for at least 5 years, and I sync the weights with its home assistant automation from the withings api, then plot the data on a custom health dashboard I made.
I’d love a local alternative, but regardless I haven’t had any problems with my setup.