@daedaevibin GrapheneOS has always used verified boot as long as it has been available. Why do you think we don't use verified boot? It's clearly listed in our hardware requirements:
https://grapheneos.org/faq#future-devices
We substantially improve the implementation rather than greatly reducing it through the LineageOS changes that are in DivestOS. It doesn't change that none of these is certified by Google. Some of our improvements to verified boot are included on our features page:
@daedaevibin The Pixel firmware and driver patches depend on Android 15 since it was released on October 15. Additionally, the full Android privacy and security devices across devices now require Android 15. Only a subset of the patches are backported to older Android releases. If you're using DivestOS on a Pixel, you're not getting current privacy/security patches. It's also a much less hardened OS than GrapheneOS with only a subset of the privacy and security features ported to LineageOS.