What I want is a system like this but set up to import all that data back into Apple Health. Each of these types of tools has their own systems for monitoring and reporting data, as you have discovered. But I only trust Apple to store my data long-term, and to keep it all on-device.

And I want support for more devices, like my Circul ring, instead of Oura. I don’t care if you have to scrape the data from their site, so long as I can import it back into Apple Health.