Does anybody know a dumbphone that also has reproducible open software builds? I've tried out a lot in the past, including FirefoxOS, KaiOS, and Bada based one

Does anybody know a dumbphone that also has reproducible open software builds? I've tried out a lot in the past, including FirefoxOS, KaiOS, and Bada based ones...but all of them are not as open as they claim to be. If they are open source, it's usually just the UI which is useless without the firmware and drivers. I would love to get a dumbphone again and hack around in it, and I saw a lot of potential in the "bananaphones" but they are more in the state of legal grey area to hack with secret GSM codes and DRM bypasses and exploits etc. KaiOS was very nice as a daily driver, even with T9 keyboard, because the occasional quick mobile internet address lookup worked, too. They also have some kind of deal with meta regarding whatsapp, and a special WhatsApp client that works, so you are not "that isolated" while still ditching all the social media apps. The general issue with KaiOS is that it only works with Firefox pre-quantum, which has so many SSL related problems that you literally have to fork the very old codebase just to get the devtools/debugger working. It's a shame, really. [1] https://sites.google.com/view/bananahackers/home https://sites.google.com/view/bananahackers/home