VMulciber "root"
It's not a "root" profile, it is the Owner profile. This profile is not more privileged than other profiles, even if it has a few extra settings. Secondary user profiles aren't designed as a security boundary, and the "isolat[ion]" offered by this feature is probably not what you think it is.
You have no access to root on GrapheneOS, and GrapheneOS cannot be rooted.
Most people don't need multiple profiles. They are recommended to be used by persona, not app category.