Cedarwood What's the current status?
It depends on what your standards of a "proper back up solution" are. Not much has changed on the Seedvault front other than minor improvements, bug fixes, etc. GrapheneOS has yet to make their own replacement for it and there is no timeline for that. They likely have many other pressing matters to focus on, like the upcoming Motorola phones that they will begin supporting, as well as the upcoming Android 17 QPR 2 update in December, etc.