I kept an eye on Seedvault development generally. There was a commit in /e/OS that did hide it from the Settings and disabled direct user activity calling ~4 years ago.
After Android 14 builds, /e/OS uses upstream Seedvault that finally does away with this and other shortcomings. I’d expect it to show up once you upgrade to the next major.
FP3 official builds were a cloaked / spoofed userbuild last I remember? you could call the activity directly as adb root if I’m not wrong on the build type. There’s an adb command in one of the linked threads that mention this. As said, nothing of this is relevant past A14: