You are referring to postmaketOS for which the project leaders themselves claim there is no flagship device where everything works as expected?
I don't know what they are referring to, I can't speak for them, but...
• postmarketOS is unrelated to Debian.
• postmarketOS is based on Alpine.
• FuriLabs does not use Alpine or postmarketOS.
• FuriOS is Droidian is a Debian derivative.
• FuriOS is Debian running on an Android kernel, with Android in a container you can stop and start on demand.
Nothing you claimed applies here.
[0]: https://pureos.net/