I was able to get multiple windows working in my flutter mac app by using the approach in this repo:
https://github.com/rodydavis/multi_window
I am working on using Device Flow to authenticate with GitHub securely without a client secret. It would be nice if more services like Hetzner had a secure way for mobile apps to login without grabbing an API key. This is less friction. AI at first tried to use something different, and blogged about that and deleted it, cause that didn’t exist, but this is the way to do it.